Hepatitis C virus inhibitors

ABSTRACT

The present disclosure relates to compounds, compositions and methods for the treatment of Hepatitis C virus (HCV) infection. Also disclosed are pharmaceutical compositions containing such compounds and methods for using these compounds in the treatment of HCV infection.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser.No. 60/938,534 filed May 17, 2007.

The present disclosure is generally directed to antiviral compounds, andmore specifically directed to compounds which can inhibit the functionof the NS5A protein encoded by Hepatitis C virus (HCV), compositionscomprising such compounds, and methods for inhibiting the function ofthe NS5A protein.

HCV is a major human pathogen, infecting an estimated 170 millionpersons worldwide—roughly five times the number infected by humanimmunodeficiency virus type 1. A substantial fraction of these HCVinfected individuals develop serious progressive liver disease,including cirrhosis and hepatocellular carcinoma.

Presently, the most effective HCV therapy employs a combination ofalpha-interferon and ribavirin, leading to sustained efficacy in 40% ofpatients. Recent clinical results demonstrate that pegylatedalpha-interferon is superior to unmodified alpha-interferon asmonotherapy. However, even with experimental therapeutic regimensinvolving combinations of pegylated alpha-interferon and ribavirin, asubstantial fraction of patients do not have a sustained reduction inviral load. Thus, there is a clear and long-felt need to developeffective therapeutics for treatment of HCV infection.

HCV is a positive-stranded RNA virus. Based on a comparison of thededuced amino acid sequence and the extensive similarity in the 5′untranslated region, HCV has been classified as a separate genus in theFlaviviridae family. All members of the Flaviviridae family haveenveloped virions that contain a positive stranded RNA genome encodingall known virus-specific proteins via translation of a single,uninterrupted, open reading frame.

Considerable heterogeneity is found within the nucleotide and encodedamino acid sequence throughout the HCV genome. At least six majorgenotypes have been characterized, and more than 50 subtypes have beendescribed. The major genotypes of HCV differ in their distributionworldwide, and the clinical significance of the genetic heterogeneity ofHCV remains elusive despite numerous studies of the possible effect ofgenotypes on pathogenesis and therapy.

The single strand HCV RNA genome is approximately 9500 nucleotides inlength and has a single open reading frame (ORF) encoding a single largepolyprotein of about 3000 amino acids. In infected cells, thispolyprotein is cleaved at multiple sites by cellular and viral proteasesto produce the structural and non-structural (NS) proteins. In the caseof HCV, the generation of mature non-structural proteins (NS2, NS3,NS4A, NS4B, NS5A, and NS5B) is effected by two viral proteases. Thefirst one is believed to be a metalloprotease and cleaves at the NS2-NS3junction; the second one is a serine protease contained within theN-terminal region of NS3 (also referred to herein as NS3 protease) andmediates all the subsequent cleavages downstream of NS3, both in cis, atthe NS3-NS4A cleavage site, and in trans, for the remaining NS4A-NS4B,NS4B-NS5A, NS5A-NS5B sites. The NS4A protein appears to serve multiplefunctions, acting as a cofactor for the NS3 protease and possiblyassisting in the membrane localization of NS3 and other viral replicasecomponents. The complex formation of the NS3 protein with NS4A seemsnecessary to the processing events, enhancing the proteolytic efficiencyat all of the sites. The NS3 protein also exhibits nucleosidetriphosphatase and RNA helicase activities. NS5B (also referred toherein as HCV polymerase) is a RNA-dependent RNA polymerase that isinvolved in the replication of HCV.

Compounds useful for treating HCV-infected patients are desired whichselectively inhibit HCV viral replication. In particular, compoundswhich are effective to inhibit the function of the NS5A protein aredesired. The HCV NS5A protein is described, for example, in Tan, S.-L.,Katzel, M. G. Virology 2001, 284, 1-12; and in Park, K.-J.; Choi, S.-H,J. Biological Chemistry 2003.

In a first aspect the present disclosure provides a compound of formula(I)

or a pharmaceutically acceptable salt thereof, wherein

A and B are each phenyl;

D and E are each five-membered aromatic rings containing one, two, orthree heteroatoms independently selected from nitrogen, oxygen, andsulfur; provided that at least one of D and E is other than imidazole;

R¹ and R² are independently selected from hydrogen and R³—C(O)—; and

each R³ is independently selected from alkoxy, alkoxyalkyl,alkoxycarbonyl, alkoxycarbonylalkyl, alkyl, alkylcarbonylalkyl, aryl,arylalkenyl, arylalkoxy, arylalkyl, aryloxyalkyl, cycloalkyl,(cycloalkyl)alkenyl, (cycloalkyl)alkyl, cycloalkyloxyalkyl, haloalkyl,heterocyclyl, heterocyclylalkenyl, heterocyclylalkoxy,heterocyclylalkyl, heterocyclyloxyalkyl, hydroxyalkyl, —NR^(c)R^(d),(NR^(c)R^(d))alkenyl, (NR^(a)R^(d))alkyl, and (NR^(a)R^(d))carbonyl.

In a first embodiment of the first aspect the present disclosureprovides a compound of Formula (I), or a pharmaceutically acceptablesalt thereof, wherein one of D and E is imidazole.

In a second embodiment of the first aspect the present disclosureprovides a compound of Formula (I), or a pharmaceutically acceptablesalt thereof, wherein at least one of D and E is selected from pyrazole,triazole, and oxadiazole.

In a third embodiment of the first aspect the present disclosureprovides a compound of Formula (I), or a pharmaceutically acceptablesalt thereof, wherein R³ is selected from alkoxy and arylalkyl.

In a second aspect the present disclosure provides a compound of Formula(II)

or a pharmaceutically acceptable salt thereof, wherein

D and E are each five-membered aromatic rings containing one, two, orthree heteroatoms independently selected from nitrogen, oxygen, andsulfur; provided that at least one of D and E is other than imidazole;

R¹ and R² are independently selected from hydrogen and R³—C(O)—; and

each R³ is independently selected from alkoxy, alkoxyalkyl,alkoxycarbonyl, alkoxycarbonylalkyl, alkyl, alkylcarbonylalkyl, aryl,arylalkenyl, arylalkoxy, arylalkyl, aryloxyalkyl, cycloalkyl,(cycloalkyl)alkenyl, (cycloalkyl)alkyl, cycloalkyloxyalkyl, haloalkyl,heterocyclyl, heterocyclylalkenyl, heterocyclylalkoxy,heterocyclylalkyl, heterocyclyloxyalkyl, hydroxyalkyl, —NR^(c)R^(d),(NR^(c)R^(d))alkenyl, (R^(c)R^(d))alkyl, and (NR^(a)R^(d))carbonyl.

In a third aspect the present disclosure provides a compound of Formula(III)

or a pharmaceutically acceptable salt thereof, wherein

D and E are each five-membered aromatic rings containing one, two, orthree heteroatoms independently selected from nitrogen, oxygen, andsulfur; provided that at least one of D and E is other than imidazole;and provided that both D and E are each substituted through carbonatoms;

R¹ and R² are independently selected from hydrogen and R³—C(O)—; and

each R³ is independently selected from alkoxy, alkoxyalkyl,alkoxycarbonyl, alkoxycarbonylalkyl, alkyl, alkylcarbonylalkyl, aryl,arylalkenyl, arylalkoxy, arylalkyl, aryloxyalkyl, cycloalkyl,(cycloalkyl)alkenyl, (cycloalkyl)alkyl, cycloalkyloxyalkyl, haloalkyl,heterocyclyl, heterocyclylalkenyl, heterocyclylalkoxy,heterocyclylalkyl, heterocyclyloxyalkyl, hydroxyalkyl, —NR^(c)R^(d),R^(c)R^(d))alkenyl, (R^(c)R^(d))alkyl, and (NR^(a)R^(d))carbonyl.

In a first embodiment of the third aspect the present disclosureprovides a compound of Formula (III), or a pharmaceutically acceptablesalt thereof, wherein

D and E are independently selected from imidazole, pyrazole, triazole,and oxadiazole; provided at least one of D and E is other thanimidazole; and provided that both D and E are each substituted throughcarbon atoms; and

R³ is selected from alkoxy and arylalkyl.

In a fourth aspect the present disclosure provides a compositioncomprising a compound of Formula (I), or a pharmaceutically acceptablesalt thereof, and a pharmaceutically acceptable carrier. In a firstembodiment of the fourth aspect the composition further comprises one ortwo additional compounds having anti-HCV activity. In a secondembodiment of the fourth aspect at least one of the additional compoundsis an interferon or a ribavirin. In a third embodiment of the fourthaspect the interferon is selected from interferon alpha 2B, pegylatedinterferon alpha, consensus interferon, interferon alpha 2A, andlymphoblastoid interferon tau.

In a fourth embodiment of the fourth aspect the disclosure provides acomposition comprising a compound of Formula (I), or a pharmaceuticallyacceptable salt thereof, a pharmaceutically acceptable carrier, and oneor two additional compounds having anti-HCV activity, wherein at leastone of the additional compounds is selected from interleukin 2,interleukin 6, interleukin 12, a compound that enhances the developmentof a type 1 helper T cell response, interfering RNA, anti-sense RNA,Imiqimod, ribavirin, an inosine 5′-monophosphate dehydrogenaseinhibitor, amantadine, and rimantadine.

In a fifth embodiment of the fourth aspect the disclosure provides acomposition comprising a compound of Formula (I), or a pharmaceuticallyacceptable salt thereof, a pharmaceutically acceptable carrier, and oneor two additional compounds having anti-HCV activity, wherein at leastone of the additional compounds is effective to inhibit the function ofa target selected from HCV metalloprotease, HCV serine protease, HCVpolymerase, HCV helicase, HCV NS4B protein, HCV entry, HCV assembly, HCVegress, HCV NS5A protein, and IMPDH for the treatment of an HCVinfection.

In a fifth aspect the present disclosure provides a method of treatingan HCV infection in a patient, comprising administering to the patient atherapeutically effective amount of a compound of Formula (I), or apharmaceutically acceptable salt thereof. In a first embodiment of thefifth aspect the method further comprises administering one or twoadditional compounds having anti-HCV activity prior to, after, orsimultaneously with the compound of Formula (I) or the pharmaceuticallyacceptable salt thereof. In a second embodiment of the fifth aspect atleast one of the additional compounds is an interferon or a ribavirin.In a third embodiment of the fifth aspect the interferon is selectedfrom interferon alpha 2B, pegylated interferon alpha, consensusinterferon, interferon alpha 2A, and lymphoblastoid interferon tau.

In a sixth aspect the present disclosure provides a method of treatingan HCV infection in a patient, comprising administering to the patient atherapeutically effective amount of a compound of Formula (I), or apharmaceutically acceptable salt thereof, and administering one or twoadditional compounds having anti-HCV activity prior to, after, orsimultaneously with the compound of Formula (I) or the pharmaceuticallyacceptable salt thereof, wherein at least one of the additionalcompounds is selected from interleukin 2, interleukin 6, interleukin 12,a compound that enhances the development of a type 1 helper T cellresponse, interfering RNA, anti-sense RNA, Imiqimod, ribavirin, aninosine 5′-monophosphate dehydrogenase inhibitor, amantadine, andrimantadine.

In a seventh aspect the present disclosure provides a method of treatingan HCV infection in a patient, comprising administering to the patient atherapeutically effective amount of a compound of Formula (I), or apharmaceutically acceptable salt thereof, and administering one or twoadditional compounds having anti-HCV activity prior to, after, orsimultaneously with the compound of Formula (I) or the pharmaceuticallyacceptable salt thereof, wherein at least one of the additionalcompounds is effective to inhibit the function of a target selected fromHCV metalloprotease, HCV serine protease, HCV polymerase, HCV helicase,HCV NS4B protein, HCV entry, HCV assembly, HCV egress, HCV NS5A protein,and IMPDH for the treatment of an HCV infection.

Other aspects of the present disclosure may include suitablecombinations of embodiments disclosed herein.

Yet other aspects and embodiments may be found in the descriptionprovided herein.

The description of the present disclosure herein should be construed incongruity with the laws and principals of chemical bonding. In someinstances it may be necessary to remove a hydrogen atom in orderaccommodate a substitutent at any given location.

It should be understood that the compounds encompassed by the presentdisclosure are those that are suitably stable for use as pharmaceuticalagent.

It is intended that the definition of any substituent or variable at aparticular location in a molecule be independent of its definitionselsewhere in that molecule. For example, when u is 2, each of the two R¹groups may be the same or different.

All patents, patent applications, and literature references cited in thespecification are herein incorporated by reference in their entirety. Inthe case of inconsistencies, the present disclosure, includingdefinitions, will prevail.

As used in the present specification, the following terms have themeanings indicated:

As used herein, the singular forms “a”, “an”, and “the” include pluralreference unless the context clearly dictates otherwise.

Unless stated otherwise, all aryl, cycloalkyl, and heterocyclyl groupsof the present disclosure may be substituted as described in each oftheir respective definitions. For example, the aryl part of an arylalkylgroup may be substituted as described in the definition of the term“aryl”.

The term “alkenyl,” as used herein, refers to a straight or branchedchain group of two to six carbon atoms containing at least onecarbon-carbon double bond.

The term “alkenyloxy,” as used herein, refers to an alkenyl groupattached to the parent molecular moiety through an oxygen atom.

The term “alkenyloxycarbonyl,” as used herein, refers to an alkenyloxygroup attached to the parent molecular moiety through a carbonyl group.

The term “alkoxy,” as used herein, refers to an alkyl group attached tothe parent molecular moiety through an oxygen atom.

The term “alkoxyalkyl,” as used herein, refers to an alkyl groupsubstituted with one, two, or three alkoxy groups.

The term “alkoxyalkylcarbonyl,” as used herein, refers to an alkoxyalkylgroup attached to the parent molecular moiety through a carbonyl group.

The term “alkoxycarbonyl,” as used herein, refers to an alkoxy groupattached to the parent molecular moiety through a carbonyl group.

The term “alkoxycarbonylalkyl,” as used herein, refers to an alkyl groupsubstituted with one, two, or three alkoxycarbonyl groups.

The term “alkyl,” as used herein, refers to a group derived from astraight or branched chain saturated hydrocarbon containing from one tosix carbon atoms.

The term “alkylcarbonyl,” as used herein, refers to an alkyl groupattached to the parent molecular moiety through a carbonyl group.

The term “alkylcarbonylalkyl,” as used herein, refers to an alkyl groupsubstituted with one, two, or three alkylcarbonyl groups.

The term “alkylcarbonyloxy,” as used herein, refers to an alkylcarbonylgroup attached to the parent molecular moiety through an oxygen atom.

The term “alkylsulfanyl,” as used herein, refers to an alkyl groupattached to the parent molecular moiety through a sulfur atom.

The term “alkylsulfonyl,” as used herein, refers to an alkyl groupattached to the parent molecular moiety through a sulfonyl group.

The term “aryl,” as used herein, refers to a phenyl group, or a bicyclicfused ring system wherein one or both of the rings is a phenyl group.Bicyclic fused ring systems consist of a phenyl group fused to a four-to six-membered aromatic or non-aromatic carbocyclic ring. The arylgroups of the present disclosure can be attached to the parent molecularmoiety through any substitutable carbon atom in the group.Representative examples of aryl groups include, but are not limited to,indanyl, indenyl, naphthyl, phenyl, and tetrahydronaphthyl. The arylgroups of the present disclosure are optionally substituted with one,two, three, four, or five substituents independently selected fromalkoxy, alkoxyalkyl, alkoxycarbonyl, alkyl, alkylcarbonyl, a second arylgroup, arylalkoxy, arylalkyl, arylcarbonyl, cyano, halo, haloalkoxy,haloalkyl, heterocyclyl, heterocyclylalkyl, heterocyclylcarbonyl,hydroxy, hydroxyalkyl, nitro, —NR^(x)R^(y), (NR^(x)R^(y))alkyl, and oxo,wherein the alkyl part of the arylalkyl and the heterocyclylalkyl areunsubstituted and wherein the second aryl group, the aryl part of thearylalkyl, the aryl part of the arylcarbonyl, the heterocyclyl, and theheterocyclyl part of the heterocyclylalkyl and the heterocyclylcarbonylare further optionally substituted with one, two, or three substituentsindependently selected from alkoxy, alkyl, cyano, halo, haloalkoxy,haloalkyl, and nitro.

The term “arylalkenyl,” as used herein, refers to an alkenyl groupsubstituted with one, two, or three aryl groups.

The term “arylalkoxy,” as used herein, refers to an aryl group attachedto the parent molecular moiety through an alkoxy group.

The term “arylalkoxyalkyl,” as used herein, refers to an alkyl groupsubstituted with one, two, or three arylalkoxy groups.

The term “arylalkoxyalkylcarbonyl,” as used herein, refers to anarylalkoxyalkyl group attached to the parent molecular moiety through acarbonyl group.

The term “arylalkoxycarbonyl,” as used herein, refers to an arylalkoxygroup attached to the parent molecular moiety through a carbonyl group.

The term “arylalkyl,” as used herein, refers to an alkyl groupsubstituted with one, two, or three aryl groups. The alkyl part of thearylalkyl is further optionally substituted with one or two additionalgroups independently selected from alkoxy, alkylcarbonyloxy, halo,haloalkoxy, haloalkyl, heterocyclyl, hydroxy, and —NR^(c)R^(d),

wherein the heterocyclyl is further optionally substituted with one ortwo substituents independently selected from alkoxy, alkyl,unsubstituted aryl, unsubstituted arylalkoxy, unsubstitutedarylalkoxycarbonyl, halo, haloalkoxy, haloalkyl, hydroxy, and—NR^(x)R^(y).

The term “arylalkylcarbonyl,” as used herein, refers to an arylalkylgroup attached to the parent molecular moiety through a carbonyl group.

The term “arylcarbonyl,” as used herein, refers to an aryl groupattached to the parent molecular moiety through a carbonyl group.

The term “aryloxy,” as used herein, refers to an aryl group attached tothe parent molecular moiety through an oxygen atom.

The term “aryloxyalkyl,” as used herein, refers to an alkyl groupsubstituted with one, two, or three aryloxy groups.

The term “aryloxycarbonyl,” as used herein, refers to an aryloxy groupattached to the parent molecular moiety through a carbonyl group.

The term “arylsulfonyl,” as used herein, refers to an aryl groupattached to the parent molecular moiety through a sulfonyl group.

The terms “Cap” and “cap”, as used herein, refer to the group which isplaced on the nitrogen atom of the pyrrolidine ring in the compounds offormula (I). It should be understood that “Cap” or “cap” can also referto the reagent which is a precursor to the final “cap” in compounds offormula (I) and is used as one of the starting materials in the reactionto append a group on the pyrrolidine nitrogen that results in the finalproduct, a compound which contains the functionalized pyrrolidine thatwill be present in the compound of formula (I).

The term “carbonyl,” as used herein, refers to —C(O)—.

The term “carboxy,” as used herein, refers to —CO₂H.

The term “cyano,” as used herein, refers to —CN.

The term “cycloalkenyl,” as used herein, refers to a non-aromatic,partially unsaturated monocyclic, bicyclic, or tricyclic ring systemhaving three to fourteen carbon atoms and zero heteroatoms.Representative examples of cycloalkenyl groups include, but are notlimited to, cyclohexenyl, octahydronaphthalenyl, and norbornylenyl.

The term “cycloalkyl,” as used herein, refers to a saturated monocyclic,hydrocarbon ring system having three to seven carbon atoms and zeroheteroatoms. Representative examples of cycloalkyl groups include, butare not limited to, cyclopropyl, cyclopentyl, and cyclohexyl. Thecycloalkyl groups of the present disclosure are optionally substitutedwith one, two, three, four, or five substituents independently selectedfrom alkoxy, alkyl, aryl, cyano, halo, haloalkoxy, haloalkyl,heterocyclyl, hydroxy, hydroxyalkyl, nitro, and —NR^(x)R^(y), whereinthe aryl and the heterocyclyl are further optionally substituted withone, two, or three substituents independently selected from alkoxy,alkyl, cyano, halo, haloalkoxy, haloalkyl, hydroxy, and nitro.

The term “(cycloalkyl)alkenyl,” as used herein, refers to an alkenylgroup substituted with one, two, or three cycloalkyl groups.

The term “(cycloalkyl)alkyl,” as used herein, refers to an alkyl groupsubstituted with one, two, or three cycloalkyl groups.

The term “cycloalkyloxy,” as used herein, refers to a cycloalkyl groupattached to the parent molecular moiety through an oxygen atom.

The term “cycloalkyloxyalkyl,” as used herein, refers to an alkyl groupsubstituted with one, two, or three cycloalkyloxy groups.

The term “cycloalkylsulfonyl,” as used herein, refers to a cycloalkylgroup attached to the parent molecular moiety through a sulfonyl group.

The term “formyl,” as used herein, refers to —CHO.

The terms “halo” and “halogen,” as used herein, refer to F, Cl, Br, orI.

The term “haloalkoxy,” as used herein, refers to a haloalkyl groupattached to the parent molecular moiety through an oxygen atom.

The term “haloalkoxycarbonyl,” as used herein, refers to a haloalkoxygroup attached to the parent molecular moiety through a carbonyl group.

The term “haloalkyl,” as used herein, refers to an alkyl groupsubstituted by one, two, three, or four halogen atoms.

The term “heterocyclyl,” as used herein, refers to a four-, five-, six-,or seven-membered ring containing one, two, three, or four heteroatomsindependently selected from nitrogen, oxygen, and sulfur. Thefour-membered ring has zero double bonds, the five-membered ring haszero to two double bonds, and the six- and seven-membered rings havezero to three double bonds. The term “heterocyclyl” also includesbicyclic groups in which the heterocyclyl ring is fused to a phenylgroup, a monocyclic cycloalkenyl group, a monocyclic cycloalkyl group,or another monocyclic heterocyclyl group. The heterocyclyl groups of thepresent disclosure can be attached to the parent molecular moietythrough a carbon atom or a nitrogen atom in the group. Examples ofheterocyclyl groups include, but are not limited to, benzothienyl,furyl, imidazolyl, indolinyl, indolyl, isothiazolyl, isoxazolyl,morpholinyl, oxazolyl, piperazinyl, piperidinyl, pyrazolyl, pyridinyl,pyrrolidinyl, pyrrolopyridinyl, pyrrolyl, thiazolyl, thienyl, andthiomorpholinyl. The heterocyclyl groups of the present disclosure areoptionally substituted with one, two, three, four, or five substituentsindependently selected from alkoxy, alkoxyalkyl, alkoxycarbonyl, alkyl,alkylcarbonyl, aryl, arylalkyl, arylcarbonyl, cyano, halo, haloalkoxy,haloalkyl, a second heterocyclyl group, heterocyclylalkyl,heterocyclylcarbonyl, hydroxy, hydroxyalkyl, nitro, —NR^(x)R^(y),(NR^(x)R^(y))alkyl, and oxo, wherein the alkyl part of the arylalkyl andthe heterocyclylalkyl are unsubstituted and wherein the aryl, the arylpart of the arylalkyl, the aryl part of the arylcarbonyl, the secondheterocyclyl group, and the heterocyclyl part of the heterocyclylalkyland the heterocyclylcarbonyl are further optionally substituted withone, two, or three substituents independently selected from alkoxy,alkyl, cyano, halo, haloalkoxy, haloalkyl, and nitro.

The term “heterocyclylalkenyl,” as used herein, refers to an alkenylgroup substituted with one, two, or three heterocyclyl groups.

The term “heterocyclylalkoxy,” as used herein, refers to a heterocyclylgroup attached to the parent molecular moiety through an alkoxy group.

The term “heterocyclylalkoxycarbonyl,” as used herein, refers to aheterocyclylalkoxy group attached to the parent molecular moiety througha carbonyl group.

The term “heterocyclylalkyl,” as used herein, refers to an alkyl groupsubstituted with one, two, or three heterocyclyl groups. The alkyl partof the heterocyclylalkyl is further optionally substituted with one ortwo additional groups independently selected from alkoxy,alkylcarbonyloxy, aryl, halo, haloalkoxy, haloalkyl, hydroxy, and—NR^(c)R^(d), wherein the aryl is further optionally substituted withone or two substituents independently selected from alkoxy, alkyl,unsubstituted aryl, unsubstituted arylalkoxy, unsubstitutedarylalkoxycarbonyl, halo, haloalkoxy, haloalkyl, hydroxy, and—NR^(x)R^(y).

The term “heterocyclylalkylcarbonyl,” as used herein, refers to aheterocyclylalkyl group attached to the parent molecular moiety througha carbonyl group.

The term “heterocyclylcarbonyl,” as used herein, refers to aheterocyclyl group attached to the parent molecular moiety through acarbonyl group.

The term “heterocyclyloxy,” as used herein, refers to a heterocyclylgroup attached to the parent molecular moiety through an oxygen atom.

The term “heterocyclyloxyalkyl,” as used herein, refers to an alkylgroup substituted with one, two, or three heterocyclyloxy groups.

The term “heterocyclyloxycarbonyl,” as used herein, refers to aheterocyclyloxy group attached to the parent molecular moiety through acarbonyl group.

The term “hydroxy,” as used herein, refers to —OH.

The term “hydroxyalkyl,” as used herein, refers to an alkyl groupsubstituted with one, two, or three hydroxy groups.

The term “hydroxyalkylcarbonyl,” as used herein, refers to ahydroxyalkyl group attached to the parent molecular moiety through acarbonyl group.

The term “nitro,” as used herein, refers to —NO₂.

The term “—NR^(c)R^(d),” as used herein, refers to two groups, R^(c) andR^(d), which are attached to the parent molecular moiety through anitrogen atom. R^(c) and R^(d) are independently selected from hydrogen,alkenyloxycarbonyl, alkoxyalkylcarbonyl, alkoxycarbonyl, alkyl,alkylcarbonyl, alkylsulfonyl, aryl, arylalkoxycarbonyl, arylalkyl,arylalkylcarbonyl, arylcarbonyl, aryloxycarbonyl, arylsulfonyl,cycloalkyl, cycloalkylsulfonyl, formyl, haloalkoxycarbonyl,heterocyclyl, heterocyclylalkoxycarbonyl, heterocyclylalkyl,heterocyclylalkylcarbonyl, heterocyclylcarbonyl,heterocyclyloxycarbonyl, hydroxyalkylcarbonyl, (NR^(e)R^(f))alkyl,(NR^(e)R^(f))alkylcarbonyl, (NR^(e)R^(f))carbonyl,(NR^(e)R^(f))sulfonyl, —C(NCN)OR′, and —C(NCN)NR^(x)R^(y), wherein R′ isselected from alkyl and unsubstituted phenyl, and wherein the alkyl partof the arylalkyl, the arylalkylcarbonyl, the heterocyclylalkyl, and theheterocyclylalkylcarbonyl are further optionally substituted with one—NR^(e)R^(f) group; and wherein the aryl, the aryl part of thearylalkoxycarbonyl, the arylalkyl, the arylalkylcarbonyl, thearylcarbonyl, the aryloxycarbonyl, and the arylsulfonyl, theheterocyclyl, and the heterocyclyl part of theheterocyclylalkoxycarbonyl, the heterocyclylalkyl, theheterocyclylalkylcarbonyl, the heterocyclylcarbonyl, and theheterocyclyloxycarbonyl are further optionally substituted with one,two, or three substituents independently selected from alkoxy, alkyl,cyano, halo, haloalkoxy, haloalkyl, and nitro.

The term “(NR^(c)R^(d))alkenyl,” as used herein, refers to an alkenylgroup substituted with one, two, or three —NR^(c)R^(d) groups.

The term “(NR^(c)R^(d))alkyl,” as used herein, refers to an alkyl groupsubstituted with one, two, or three —NR^(c)R^(d) groups. The alkyl partof the (NR^(c)R^(d))alkyl is further optionally substituted with one ortwo additional groups selected from alkoxy, alkoxyalkylcarbonyl,alkoxycarbonyl, alkylsulfanyl, arylalkoxyalkylcarbonyl, carboxy,heterocyclyl, heterocyclylcarbonyl, hydroxy, and (NR^(e)R^(f))carbonyl;wherein the heterocyclyl is further optionally substituted with one,two, three, four, or five substituents independently selected fromalkoxy, alkyl, cyano, halo, haloalkoxy, haloalkyl, and nitro.

The term “(NR^(c)R^(d))carbonyl,” as used herein, refers to an—NR^(c)R^(d) group attached to the parent molecular moiety through acarbonyl group.

The term “—NR^(e)R^(f),” as used herein, refers to two groups, R^(e) andR^(f) which are attached to the parent molecular moiety through anitrogen atom. R^(e) and R^(f) are independently selected from hydrogen,alkyl, unsubstituted aryl, unsubstituted arylalkyl, unsubstitutedcycloalkyl, unsubstituted (cyclolalkyl)alkyl, unsubstitutedheterocyclyl, unsubstituted heterocyclylalkyl, (NR^(x)R^(y))alkyl, and(NR^(x)R^(y))carbonyl.

The term “(NR^(e)R^(f))alkyl,” as used herein, refers to an alkyl groupsubstituted with one, two, or three —NR^(e)R^(f) groups.

The term “(NR^(e)R^(f))alkylcarbonyl,” as used herein, refers to an(NR^(e)R^(f))alkyl group attached to the parent molecular moiety througha carbonyl group.

The term “(NR^(e)R^(f))carbonyl,” as used herein, refers to an—NR^(e)R^(f) group attached to the parent molecular moiety through acarbonyl group.

The term “(NR^(e)R^(f))sulfonyl,” as used herein, refers to an—NR^(e)R^(f) group attached to the parent molecular moiety through asulfonyl group.

The term “—NR^(x)R^(y),” as used herein, refers to two groups, R^(x) andR^(y), which are attached to the parent molecular moiety through anitrogen atom. R^(x) and R^(y) are independently selected from hydrogen,alkoxycarbonyl, alkyl, alkylcarbonyl, unsubstituted aryl, unsubstitutedarylalkoxycarbonyl, unsubstituted arylalkyl, unsubstituted cycloalkyl,unsubstituted heterocyclyl, and (NR^(x′)R^(y′))carbonyl, wherein R^(x′)and R^(y′) are independently selected from hydrogen and alkyl.

The term “(NR^(x)R^(y))alkyl,” as used herein, refers to an alkyl groupsubstituted with one, two, or three —NR^(x)R^(y) groups.

The term “(NR^(x)R^(y))carbonyl,” as used herein, refers to an—NR^(x)R^(y) group attached to the parent molecular moiety through acarbonyl group.

The term “oxo,” as used herein, refers to ═O.

The term “sulfonyl,” as used herein, refers to —SO₂—.

Asymmetric centers exist in the compounds of the present disclosure.These centers are designated by the symbols “R” or “S”, depending on theconfiguration of substituents around the chiral carbon atom. It shouldbe understood that the disclosure encompasses all stereochemicalisomeric forms, or mixtures thereof, which possess the ability toinhibit NS5A. Individual stereoisomers of compounds can be preparedsynthetically from commercially available starting materials whichcontain chiral centers or by preparation of mixtures of enantiomericproducts followed by separation such as conversion to a mixture ofdiastereomers followed by separation or recrystallization,chromatographic techniques, or direct separation of enantiomers onchiral chromatographic columns. Starting compounds of particularstereochemistry are either commercially available or can be made andresolved by techniques known in the art.

Certain compounds of the present disclosure may also exist in differentstable conformational forms which may be separable. Torsional asymmetrydue to restricted rotation about an asymmetric single bond, for examplebecause of steric hindrance or ring strain, may permit separation ofdifferent conformers. The present disclosure includes eachconformational isomer of these compounds and mixtures thereof.

The term “compounds of the present disclosure”, and equivalentexpressions, are meant to embrace compounds of Formula (I), andpharmaceutically acceptable enantiomers, diastereomers, and saltsthereof. Similarly, references to intermediates are meant to embracetheir salts where the context so permits.

The compounds of the present disclosure can exist as pharmaceuticallyacceptable salts. The term “pharmaceutically acceptable salt,” as usedherein, represents salts or zwitterionic forms of the compounds of thepresent disclosure which are water or oil-soluble or dispersible, whichare, within the scope of sound medical judgment, suitable for use incontact with the tissues of patients without excessive toxicity,irritation, allergic response, or other problem or complicationcommensurate with a reasonable benefit/risk ratio, and are effective fortheir intended use The salts can be prepared during the final isolationand purification of the compounds or separately by reacting a suitablenitrogen atom with a suitable acid. Representative acid addition saltsinclude acetate, adipate, alginate, citrate, aspartate, benzoate,benzenesulfonate, bisulfate, butyrate, camphorate, camphorsulfonate;digluconate, glycerophosphate, hemisulfate, heptanoate, hexanoate,formate, fumarate, hydrochloride, hydrobromide, hydroiodide,2-hydroxyethanesulfonate, lactate, maleate, mesitylenesulfonate,methanesulfonate, naphthylenesulfonate, nicotinate,2-naphthalenesulfonate, oxalate, palmoate, pectinate, persulfate,3-phenylproprionate, picrate, pivalate, propionate, succinate, tartrate,trichloroacetate, trifluoroacetate, phosphate, glutamate, bicarbonate,para-toluenesulfonate, and undecanoate. Examples of acids which can beemployed to form pharmaceutically acceptable addition salts includeinorganic acids such as hydrochloric, hydrobromic, sulfuric, andphosphoric, and organic acids such as oxalic, maleic, succinic, andcitric.

Basic addition salts can be prepared during the final isolation andpurification of the compounds by reacting a carboxy group with asuitable base such as the hydroxide, carbonate, or bicarbonate of ametal cation or with ammonia or an organic primary, secondary, ortertiary amine. The cations of pharmaceutically acceptable salts includelithium, sodium, potassium, calcium, magnesium, and aluminum, as well asnontoxic quaternary amine cations such as ammonium, tetramethylammonium,tetraethylammonium, methylamine, dimethylamine, trimethylamine,triethylamine, diethylamine, ethylamine, tributylamine, pyridine,N,N-dimethylaniline, N-methylpiperidine, N-methylmorpholine,dicyclohexylamine, procaine, dibenzylamine, N,N-dibenzylphenethylamine,and N,N′-dibenzylethylenediamine. Other representative organic aminesuseful for the formation of base addition salts include ethylenediamine,ethanolamine, diethanolamine, piperidine, and piperazine.

When it is possible that, for use in therapy, therapeutically effectiveamounts of a compound of Formula (I), as well as pharmaceuticallyacceptable salts thereof, may be administered as the raw chemical, it ispossible to present the active ingredient as a pharmaceuticalcomposition. Accordingly, the disclosure further provides pharmaceuticalcompositions, which include therapeutically effective amounts ofcompounds of Formula (I) or pharmaceutically acceptable salts thereof,and one or more pharmaceutically acceptable carriers, diluents, orexcipients. The term “therapeutically effective amount,” as used herein,refers to the total amount of each active component that is sufficientto show a meaningful patient benefit, e.g., a sustained reduction inviral load. When applied to an individual active ingredient,administered alone, the term refers to that ingredient alone. Whenapplied to a combination, the term refers to combined amounts of theactive ingredients that result in the therapeutic effect, whetheradministered in combination, serially, or simultaneously. The compoundsof Formula (I) and pharmaceutically acceptable salts thereof, are asdescribed above. The carrier(s), diluent(s), or excipient(s) must beacceptable in the sense of being compatible with the other ingredientsof the formulation and not deleterious to the recipient thereof. Inaccordance with another aspect of the present disclosure there is alsoprovided a process for the preparation of a pharmaceutical formulationincluding admixing a compound of Formula (I), or a pharmaceuticallyacceptable salt thereof, with one or more pharmaceutically acceptablecarriers, diluents, or excipients. The term “pharmaceuticallyacceptable,” as used herein, refers to those compounds, materials,compositions, and/or dosage forms which are, within the scope of soundmedical judgment, suitable for use in contact with the tissues ofpatients without excessive toxicity, irritation, allergic response, orother problem or complication commensurate with a reasonablebenefit/risk ratio, and are effective for their intended use.

Pharmaceutical formulations may be presented in unit dose formscontaining a predetermined amount of active ingredient per unit dose.Dosage levels of between about 0.01 and about 250 milligram per kilogram(“mg/kg”) body weight per day, preferably between about 0.05 and about100 mg/kg body weight per day of the compounds of the present disclosureare typical in a monotherapy for the prevention and treatment of HCVmediated disease. Typically, the pharmaceutical compositions of thisdisclosure will be administered from about 1 to about 5 times per day oralternatively, as a continuous infusion. Such administration can be usedas a chronic or acute therapy. The amount of active ingredient that maybe combined with the carrier materials to produce a single dosage formwill vary depending on the condition being treated, the severity of thecondition, the time of administration, the route of administration, therate of excretion of the compound employed, the duration of treatment,and the age, gender, weight, and condition of the patient. Preferredunit dosage formulations are those containing a daily dose or sub-dose,as herein above recited, or an appropriate fraction thereof, of anactive ingredient. Generally, treatment is initiated with small dosagessubstantially less than the optimum dose of the compound. Thereafter,the dosage is increased by small increments until the optimum effectunder the circumstances is reached. In general, the compound is mostdesirably administered at a concentration level that will generallyafford antivirally effective results without causing any harmful ordeleterious side effects.

When the compositions of this disclosure comprise a combination of acompound of the present disclosure and one or more additionaltherapeutic or prophylactic agent, both the compound and the additionalagent are usually present at dosage levels of between about 10 to 150%,and more preferably between about 10 and 80% of the dosage normallyadministered in a monotherapy regimen.

Pharmaceutical formulations may be adapted for administration by anyappropriate route, for example by the oral (including buccal orsublingual), rectal, nasal, topical (including buccal, sublingual, ortransdermal), vaginal, or parenteral (including subcutaneous,intracutaneous, intramuscular, intra-articular, intrasynovial,intrasternal, intrathecal, intralesional, intravenous, or intradermalinjections or infusions) route. Such formulations may be prepared by anymethod known in the art of pharmacy, for example by bringing intoassociation the active ingredient with the carrier(s) or excipient(s).Oral administration or administration by injection are preferred.

Pharmaceutical formulations adapted for oral administration may bepresented as discrete units such as capsules or tablets; powders orgranules; solutions or suspensions in aqueous or non-aqueous liquids;edible foams or whips; or oil-in-water liquid emulsions or water-in-oilemulsions.

For instance, for oral administration in the form of a tablet orcapsule, the active drug component can be combined with an oral,non-toxic pharmaceutically acceptable inert carrier such as ethanol,glycerol, water, and the like. Powders are prepared by comminuting thecompound to a suitable fine size and mixing with a similarly comminutedpharmaceutical carrier such as an edible carbohydrate, as, for example,starch or mannitol. Flavoring, preservative, dispersing, and coloringagent can also be present.

Capsules are made by preparing a powder mixture, as described above, andfilling formed gelatin sheaths. Glidants and lubricants such ascolloidal silica, talc, magnesium stearate, calcium stearate, or solidpolyethylene glycol can be added to the powder mixture before thefilling operation. A disintegrating or solubilizing agent such asagar-agar, calcium carbonate, or sodium carbonate can also be added toimprove the availability of the medicament when the capsule is ingested.

Moreover, when desired or necessary, suitable binders, lubricants,disintegrating agents, and coloring agents can also be incorporated intothe mixture. Suitable binders include starch, gelatin, natural sugarssuch as glucose or beta-lactose, corn sweeteners, natural and syntheticgums such as acacia, tragacanth or sodium alginate,carboxymethylcellulose, polyethylene glycol, and the like. Lubricantsused in these dosage forms include sodium oleate, sodium chloride, andthe like. Disintegrators include, without limitation, starch, methylcellulose, agar, betonite, xanthan gum, and the like. Tablets areformulated, for example, by preparing a powder mixture, granulating orslugging, adding a lubricant and disintegrant, and pressing intotablets. A powder mixture is prepared by mixing the compound, suitablecomminuted, with a diluent or base as described above, and optionally,with a binder such as carboxymethylcellulose, an aliginate, gelating, orpolyvinyl pyrrolidone, a solution retardant such as paraffin, aresorption accelerator such as a quaternary salt and/or and absorptionagent such as betonite, kaolin, or dicalcium phosphate. The powdermixture can be granulated by wetting with a binder such as syrup, starchpaste, acadia mucilage, or solutions of cellulosic or polymericmaterials and forcing through a screen. As an alternative togranulating, the powder mixture can be run through the tablet machineand the result is imperfectly formed slugs broken into granules. Thegranules can be lubricated to prevent sticking to the tablet formingdies by means of the addition of stearic acid, a stearate salt, talc, ormineral oil. The lubricated mixture is then compressed into tablets. Thecompounds of the present disclosure can also be combined with a freeflowing inert carrier and compressed into tablets directly without goingthrough the granulating or slugging steps. A clear or opaque protectivecoating consisting of a sealing coat of shellac, a coating of sugar orpolymeric material, and a polish coating of wax can be provided.Dyestuffs can be added to these coatings to distinguish different unitdosages.

Oral fluids such as solution, syrups, and elixirs can be prepared indosage unit form so that a given quantity contains a predeterminedamount of the compound. Syrups can be prepared by dissolving thecompound in a suitably flavored aqueous solution, while elixirs areprepared through the use of a non-toxic vehicle. Solubilizers andemulsifiers such as ethoxylated isostearyl alcohols and polyoxyethylenesorbitol ethers, preservatives, flavor additive such as peppermint oilor natural sweeteners, or saccharin or other artificial sweeteners, andthe like can also be added.

Where appropriate, dosage unit formulations for oral administration canbe microencapsulated. The formulation can also be prepared to prolong orsustain the release as for example by coating or embedding particulatematerial in polymers, wax, or the like.

The compounds of Formula (I), and pharmaceutically acceptable saltsthereof, can also be administered in the form of liposome deliverysystems, such as small unilamellar vesicles, large unilamellar vesicles,and multilamellar vesicles. Liposomes can be formed from a variety ofphopholipids, such as cholesterol, stearylamine, or phophatidylcholines.

The compounds of Formula (I) and pharmaceutically acceptable saltsthereof may also be delivered by the use of monoclonal antibodies asindividual carriers to which the compound molecules are coupled. Thecompounds may also be coupled with soluble polymers as targetable drugcarriers. Such polymers can include polyvinylpyrrolidone, pyrancopolymer, polyhydroxypropylmethacrylamidephenol,polyhydroxyethylaspartamidephenol, or polyethyleneoxidepolylysinesubstituted with palitoyl residues. Furthermore, the compounds may becoupled to a class of biodegradable polymers useful in achievingcontrolled release of a drug, for example, polylactic acid, polepsiloncaprolactone, polyhydroxy butyric acid, polyorthoesters, polyacetals,polydihydropyrans, polycyanoacrylates, and cross-linked or amphipathicblock copolymers of hydrogels.

Pharmaceutical formulations adapted for transdermal administration maybe presented as discrete patches intended to remain in intimate contactwith the epidermis of the recipient for a prolonged period of time. Forexample, the active ingredient may be delivered from the patch byiontophoresis as generally described in Pharmaceutical Research 1986,3(6), 318.

Pharmaceutical formulations adapted for topical administration may beformulated as ointments, creams, suspensions, lotions, powders,solutions, pastes, gels, sprays, aerosols, or oils.

For treatments of the eye or other external tissues, for example mouthand skin, the formulations are preferably applied as a topical ointmentor cream. When formulated in an ointment, the active ingredient may beemployed with either a paraffinic or a water-miscible ointment base.Alternatively, the active ingredient may be formulated in a cream withan oil-in-water cream base or a water-in oil base.

Pharmaceutical formulations adapted for topical administrations to theeye include eye drops wherein the active ingredient is dissolved orsuspended in a suitable carrier, especially an aqueous solvent.

Pharmaceutical formulations adapted for topical administration in themouth include lozenges, pastilles, and mouth washes.

Pharmaceutical formulations adapted for rectal administration may bepresented as suppositories or as enemas.

Pharmaceutical formulations adapted for nasal administration wherein thecarrier is a solid include a course powder having a particle size forexample in the range 20 to 500 microns which is administered in themanner in which snuff is taken, i.e., by rapid inhalation through thenasal passage from a container of the powder held close up to the nose.Suitable formulations wherein the carrier is a liquid, foradministration as a nasal spray or nasal drops, include aqueous or oilsolutions of the active ingredient.

Pharmaceutical formulations adapted for administration by inhalationinclude fine particle dusts or mists, which may be generated by means ofvarious types of metered, dose pressurized aerosols, nebulizers, orinsufflators.

Pharmaceutical formulations adapted for vaginal administration may bepresented as pessaries, tampons, creams, gels, pastes, foams, or sprayformulations.

Pharmaceutical formulations adapted for parenteral administrationinclude aqueous and non-aqueous sterile injection solutions which maycontain anti-oxidants, buffers, bacteriostats, and soutes which renderthe formulation isotonic with the blood of the intended recipient; andaqueous and non-aqueous sterile suspensions which may include suspendingagents and thickening agents. The formulations may be presented inunit-dose or multi-dose containers, for example sealed ampoules andvials, and may be stored in a freeze-dried (lyophilized) conditionrequiring only the addition of the sterile liquid carrier, for examplewater for injections, immediately prior to use. Extemporaneous injectionsolutions and suspensions may be prepared from sterile powders,granules, and tablets.

It should be understood that in addition to the ingredients particularlymentioned above, the formulations may include other agents conventionalin the art having regard to the type of formulation in question, forexample those suitable for oral administration may include flavoringagents.

The term “patient” includes both human and other mammals.

The term “treating” refers to: (i) preventing a disease, disorder orcondition from occurring in a patient that may be predisposed to thedisease, disorder, and/or condition but has not yet been diagnosed ashaving it; (ii) inhibiting the disease, disorder, or condition, i.e.,arresting its development; and (iii) relieving the disease, disorder, orcondition, i.e., causing regression of the disease, disorder, and/orcondition.

The compounds of the present disclosure can also be administered with acyclosporin, for example, cyclosporin A. Cyclosporin A has been shown tobe active against HCV in clinical trials (Hepatology 2003, 38, 1282;Biochem. Biophys. Res. Commun. 2004, 313, 42; J Gastroenterol. 2003, 38,567).

Table 1 below lists some illustrative examples of compounds that can beadministered with the compounds of this disclosure. The compounds of thedisclosure can be administered with other anti-HCV activity compounds incombination therapy, either jointly or separately, or by combining thecompounds into a composition.

TABLE 1 Type of Inhibitor or Source Brand Name Physiological ClassTarget Company NIM811 Cyclophilin Inhibitor Novartis ZadaxinImmunomodulator Sciclone Suvus Methylene blue Bioenvision Actilon(CPG10101) TLR9 agonist Coley Batabutlin (T67) Anticancer β-tubulininhibitor Tularik Inc., South San Francisco, CA ISIS 14803 Antiviralantisense ISIS Pharmaceuticals Inc, Carlsbad, CA/Elan PhamaceuticalsInc., New York, NY Summetrel Antiviral antiviral Endo PharmaceuticalsHoldings Inc., Chadds Ford, PA GS-9132 (ACH-806) Antiviral HCV InhibitorAchillion/ Gilead Pyrazolopyrimidine Antiviral HCV Inhibitors Arrowcompounds and salts Therapeutics From WO-2005047288 Ltd. 26 May 2005Levovirin Antiviral IMPDH inhibitor Ribapharm Inc., Costa Mesa, CAMerimepodib Antiviral IMPDH inhibitor Vertex (VX-497) PharmaceuticalsInc., Cambridge, MA XTL-6865 (XTL-002) Antiviral monoclonal antibody XTLBiopharmaceuticals Ltd., Rehovot, Isreal Telaprevir Antiviral NS3 serineprotease Vertex (VX-950, LY-570310) inhibitor Pharmaceuticals Inc.,Cambridge, MA/Eli Lilly and Co. Inc., Indianapolis, IN HCV-796 AntiviralNS5B Replicase Wyeth/ Inhibitor Viropharma NM-283 Antiviral NS5BReplicase Idenix/ Inhibitor Novartis GL-59728 Antiviral NS5B ReplicaseGene Labs/ Inhibitor Novartis GL-60667 Antiviral NS5B Replicase GeneLabs/ Inhibitor Novartis 2′C MeA Antiviral NS5B Replicase GileadInhibitor PSI 6130 Antiviral NS5B Replicase Roche Inhibitor R1626Antiviral NS5B Replicase Roche Inhibitor 2′C Methyl adenosine AntiviralNS5B Replicase Merck Inhibitor JTK-003 Antiviral RdRp inhibitor JapanTobacco Inc., Tokyo, Japan Levovirin Antiviral ribavirin ICNPharmaceuticals, Costa Mesa, CA Ribavirin Antiviral ribavirin Schering-Plough Corporation, Kenilworth, NJ Viramidine Antiviral RibavirinProdrug Ribapharm Inc., Costa Mesa, CA Heptazyme Antiviral ribozymeRibozyme Pharmaceuticals Inc., Boulder, CO BILN-2061 Antiviral serineprotease Boehringer inhibitor Ingelheim Pharma KG, Ingelheim, GermanySCH 503034 Antiviral serine protease Schering inhibitor Plough ZadazimImmune modulator Immune modulator SciClone Pharmaceuticals Inc., SanMateo, CA Ceplene Immunomodulator immune modulator Maxim PharmaceuticalsInc., San Diego, CA CellCept Immunosuppressant HCV IgG F. Hoffmann-immunosuppressant La Roche LTD, Basel, Switzerland CivacirImmunosuppressant HCV IgG Nabi immunosuppressant BiopharmaceuticalsInc., Boca Raton, FL Albuferon-α Interferon albumin IFN-α2b Human GenomeSciences Inc., Rockville, MD Infergen A Interferon IFN alfacon-1InterMune Pharmaceuticals Inc., Brisbane, CA Omega IFN Interferon IFN-ωIntarcia Therapeutics IFN-β and EMZ701 Interferon IFN-β and EMZ701Transition Therapeutics Inc., Ontario, Canada Rebif Interferon IFN-β1aSerono, Geneva, Switzerland Roferon A Interferon IFN-α2a F. Hoffmann- LaRoche LTD, Basel, Switzerland Intron A Interferon IFN-α2b Schering-Plough Corporation, Kenilworth, NJ Intron A and Zadaxin InterferonIFN-α2b/α1-thymosin RegeneRx Biopharmiceuticals Inc., Bethesda, MD/SciClone Pharmaceuticals Inc, San Mateo, CA Rebetron InterferonIFN-α2b/ribavirin Schering- Plough Corporation, Kenilworth, NJ ActimmuneInterferon INF-γ InterMune Inc., Brisbane, CA Interferon-β InterferonInterferon-β-1a Serono Multiferon Interferon Long lasting IFNViragen/Valentis Wellferon Interferon lymphoblastoid IFN-GlaxoSmithKline αn1 plc, Uxbridge, UK Omniferon Interferon natural IFN-αViragen Inc., Plantation, FL Pegasys Interferon PEGylated IFN-α2a F.Hoffmann- La Roche LTD, Basel, Switzerland Pegasys and CepleneInterferon PEGylated IFN-α2a/ Maxim immune modulator PharmaceuticalsInc., San Diego, CA Pegasys and Ribavirin Interferon PEGylated IFN- F.Hoffmann- α2a/ribavirin La Roche LTD, Basel, Switzerland PEG-IntronInterferon PEGylated IFN-α2b Schering- Plough Corporation, Kenilworth,NJ PEG-Intron/Ribavirin Interferon PEGylated IFN- Schering-α2b/ribavirin Plough Corporation, Kenilworth, NJ IP-501 Liver protectionantifibrotic Indevus Pharmaceuticals Inc., Lexington, MA IDN-6556 Liverprotection caspase inhibitor Idun Pharmaceuticals Inc., San Diego, CA

The compounds of the present disclosure may also be used as laboratoryreagents. Compounds may be instrumental in providing research tools fordesigning of viral replication assays, validation of animal assaysystems and structural biology studies to further enhance knowledge ofthe HCV disease mechanisms. Further, the compounds of the presentdisclosure are useful in establishing or determining the binding site ofother antiviral compounds, for example, by competitive inhibition.

The compounds of this disclosure may also be used to treat or preventviral contamination of materials and therefore reduce the risk of viralinfection of laboratory or medical personnel or patients who come incontact with such materials, e.g., blood, tissue, surgical instrumentsand garments, laboratory instruments and garments, and blood collectionor transfusion apparatuses and materials.

This disclosure is intended to encompass compounds having Formula (I)when prepared by synthetic processes or by metabolic processes includingthose occurring in the human or animal body (in vivo) or processesoccurring in vitro.

The abbreviations used in the present application, includingparticularly in the illustrative examples which follow, are well-knownto those skilled in the art. Some of the abbreviations used are asfollows: TEA and NEt₃ for triethylamine; DMF for N,N-dimethylformamide;THF for tetrahydrofuran; HATU forO-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluroniumhexafluorophosphate; Et for ethyl; Boc or BOC for tert-butoxycarbonyl;Me for methyl; EtOH for ethanol; DMSO for dimethylsulfoxide; MeOH formethanol; MeLi for methyllithium; tBuLi or tert-BuLi fortert-butyllithium; TFA for trifluoroacetic acid; Et₂O for diethyl ether;Ph for phenyl; OAc for acetate; DME for 1,2-dimethoxyethane; DEPBT for3-(diethoxyphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one; iPr₂EtN or DIPEAfor diisopropylethylamine; EDCI for1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride; DMAP for4-dimethylaminopyridine; DBU for 1,8-diazabicyclo[5.4.0]undec-7-ene;t-Bu for tert-butyl; and HMDS for hexamethyldisilazide.

The present disclosure will now be described in connection with certainembodiments which are not intended to limit its scope. On the contrary,the present disclosure covers all alternatives, modifications, andequivalents as can be included within the scope of the claims. Thus, thefollowing examples, which include specific embodiments, will illustrateone practice of the present disclosure, it being understood that theexamples are for the purposes of illustration of certain embodiments andare presented to provide what is believed to be the most useful andreadily understood description of its procedures and conceptual aspects.

Starting materials can be obtained from commercial sources or preparedby well-established literature methods known to those of ordinary skillin the art.

EXAMPLES Preparation of Intermediate 4: (S)-tert-butyl2-(5-(4-bromophenyl)-1H-pyrazol-3-yl)pyrrolidine-1-carboxylate

Step 1: To a solution of 4-bromophenylacetylene (1) (0.917 g, 5.06 mmol)in THF (20 mL) at 0° C. was added dropwise a solution of ethyl magnesiumbromide (3M in THF, 1.8 mL, 5.4 mmol). After 10 minutes the cooling bathwas removed and the mixture allowed to stir at room temperature for 1hour. The reaction mixture was then recooled to 0° C. and added to asolution of N-(tert-butoxycarbonyl)-L-proline-N′-methoxy-N′-methylamide(2) (0.970 g, 3.76 mmol) in THF (10 mL). The reaction mixture was warmedto room temperature, allowed to stir for 2 hours and then quenched withsaturated NH₄Cl. The mixture was diluted with ethyl acetate/H₂O and thelayers separated. The aqueous phase was back-extracted with ethylacetate (2×) and the combined organic layers were washed (H₂O, brine),dried (Na₂SO₄), and filtered. The solvent was removed in vacuo and theresidue purified by flash chromatography (hexane:ethyl acetate, 4:1) togive intermediate (3) as a cream colored solid (1.26 g, 89%). ¹H NMR(400 MHz, DMSO-d₆) δ 7.71-7.73 (m, 2H), 4.26-4.32 (m, 1H), 3.39-3.49 (m,2H), 2.20-2.32 (m, 1H), 1.81-2.00 (m, 3H), 1.36, 1.31 (s, 9H, rotamersin 2:3 ratio); LCMS: Anal. Calcd. for C₁₈H₂₀BrNO₃: 377. found: 278(M+H-Boc)⁺.

Step 2: A mixture of (S)-tert-butyl2-(3-(4-bromophenyl)propioloyl)pyrrolidine-1-carboxylate (3) (0.759 g,2.01 mmol) and hydrazine hydrate (55% w/w aqueous solution, 0.19 mL,2.15 mmol) in ethanol (10 mL) was heated at 80° C. for 16 hours. Thesolvent was then removed and the residue was partitioned with ethylacetate/H₂O. The aqueous phase was re-extracted with ethyl acetate (2×)and the combined organic layers were washed (H₂O, brine), dried(Na₂SO₄), and filtered. The solvent was removed in vacuo to provideintermediate (4) as a colorless foam (0.812 g, quant.; ¹H NMR indicatedthe presence of residual ethyl acetate.); ¹H NMR (400 MHz, DMSO-d₆) δ13.0 (s, 0.4H), 12.8 (s, 0.6H), 7.54-7.73 (m, 4H), 6.50 (s, 1H), 4.8 (m,1H), 3.50 (s, br, 1H), 2.17 (s, br, 1H), 1.84-1.88 (m, 3H), 1.38, 1.18(s, 9H, rotamers in 2:3 ratio); LCMS: Anal. Calcd. for C₁₈H₂₂BrN₃O₂:391. found: 392 (M+H)⁺.

Preparation of Intermediate 8: (S)-tert-Butyl2-(5-(4-iodophenyl)-1H-pyrazol-3-yl)pyrrolidine-1-carboxylate

Step 1: To a solution of ((4-iodophenyl)ethynyl)trimethylsilane (5)(2.07 g, 6.23 mmol) in methanol (40 mL) was added K₂CO₃ (8.0 g, 57.9mmol) and the reaction was allowed to stir for 48 hours. The volatileswere then removed in vacuo and the residue partitioned between ethylacetate and H₂O. The layers were separated and the aqueous phasere-extracted with ethyl acetate (2×). The combined organic layers werewashed (H₂O, brine), dried (Na₂SO₄), and filtered. The solvent wasremoved in vacuo and the residue was crystallized from hexane at −20° C.(in 2 crops) to give 1-ethynyl-4-iodobenzene (6) as a colorless solid(0.92 g, 64%). ¹H NMR (400 MHz, DMSO-d₆) δ 7.66 (app d, J=8.6 Hz, 2H),7.20 (app d, J=8.5 Hz, 2H), 1.54 (s, 1H).

Step 2: To a solution of 1-ethynyl-4-iodobenzene 6 (0.908 g, 3.98 mmol)in THF (20 mL) at −78° C. was added ethylmagnesium bromide (3M in ether,1.39 mL, 4.18 mmol). After 10 minutes the cooling bath was removed andthe solution was allowed to stir at room temperature for 1 hour. Thereaction mixture was then re-cooled to 0° C. and added to a solution ofN-(tert-butoxycarbonyl)-L-proline N′-methoxy-N′-methylamide 2 (0.970 g,3.76 mmol) in THF (10 mL). The reaction mixture was warmed to roomtemperature and stirring was continued for 12 hours before the mixturewas quenched with saturated NH₄Cl. The mixture was diluted with ethylacetate/H₂O, the layers separated and the aqueous phase was re-extractedwith ethyl acetate (2×). The combined organic layers were washed (H₂O,brine), dried (Na₂SO₄), and filtered, and the solvent was removed invacuo. The resulting residue was purified by flash chromatography(hexane:ethyl acetate, 4:1) to give (S)-tert-butyl2-(3-(4-iodophenyl)propioloyl)pyrrolidine-1-carboxylate 7 (0.908 g, 71%)as a yellow oil which solidified on standing. ¹H NMR (400 MHz, CDCl₃) δ7.72-7.76 (m, 2H), 7.26-7.30 (m, 2H), 4.49 (dd, J=8.8, 4.3 Hz, 0.3H),4.29 (dd, J=8.5, 5.5 Hz, 0.7H), 3.59 (app t, J=6.7 Hz, 2H), 2.20-2.33(m, 1H), 1.85-2.10 (m, 3H), 1.45, 1.40 (s, 9H, rotamers in 2:3 ratio).LCMS: Anal. Calcd. for C₁₈H₂₀INO₃: 425. found: 326 (M+H-Boc)⁺.

Step 3: A solution of (S)-tert-butyl2-(3-(4-iodophenyl)propioloyl)pyrrolidine-1-carboxylate 7 (0.905 g, 2.13mmol) and hydrazine (55% w/w aqueous solution, 0.21 mL, 2.25 mmol) inethanol (20 mL) was heated at 85° C. for 3 hours. The solvent was thenremoved in vacuo and the residue was partitioned with H₂O/ethyl acetate.The layers were separated and the aqueous phase was re-extracted withethyl acetate (2×) and the combined organic layers were washed (H₂O,brine), dried (Na₂SO₄), and filtered. The solvent was removed in vacuoto give the title compound 8 (0.966 g, quant.) as a colorless foam. ¹HNMR (400 MHz, CDCl₃) δ 7.70 (app d, J=8.2 Hz, 2H), 7.51 (app d, J=8.2Hz, 2H), 6.36 (s, 1H), 4.94-5.02 (m, 1H), 3.38-3.55 (m, 2H), 2.25-2.29(m, 2H), 1.89-2.05 (m, 2H). LCMS: Anal. Calcd. for C₁₈H₂₂IN₃O₂: 439.found: 340 (M+H-Boc)⁺.

Preparation of Intermediate 9a:4,4′-bis(3-((S)-pyrrolidin-2-yl)-1H-pyrazol-5-yl)biphenyl

Step 1: To a solution of (S)-tert-butyl2-(5-(4-bromophenyl)-1H-pyrazol-3-yl)pyrrolidine-1-carboxylate (4)(0.187 g, 0.476 mmol) in THF (5 mL) at −78° C. was added MeLi (1.6M inEt₂O, 0.31 mL, 0.496 mmol), followed by tert-BuLi (1.7M in pentane, 0.64mL, 1.09 mmol). After 10 min, a solution of freshly fused ZnCl₂ (0.091g, 0.668 mmol) in THF (2 mL) was added via cannula. The solution wasallowed to stir for 30 minutes and then the cooling bath was removed andthe solution allowed to warm to room temperature. To this mixture wasadded (S)-tert-butyl2-(5-(4-iodophenyl)-1H-pyrazol-3-yl)pyrrolidine-1-carboxylate (8) (0.305g, 0.694 mmol) and Pd(PPh₃)₄ (0.032 g, 0.0277 mmol) and the mixture washeated at 70° C. under Ar for 12 hours. After cooling to roomtemperature, saturated NH₄Cl was added and the mixture was partitionedwith ethyl acetate/H₂O. The aqueous phase was separated and re-extractedwith ethyl acetate (2×), and the combined organic layers were washed(H₂O, brine), dried (Na₂SO₄), and filtered. The solvent was removed invacuo and the residue was purified by flash chromatography (0-100% ethylacetate-hexane) and then repurified using preparative HPLC(CH₃CN:H₂O:NH₄OAc) to give an oil which was a mixture of the desiredproduct (9) and the starting aryliodide (8) (ca. 1:1 by LCMS). ¹H NMR(400 MHz, CD₃OD) δ 7.80 (s, br, 2H), 7.73 (s, br, 2H), 7.61-7.66 (m,2H), 7.52-7.57 (m, 2H), 6.50 (s, 2H), 4.8 (m, 2H, partially obscured bysolvent), 3.61-3.63 (m, 2H), 3.47-3.51 (m, 2H), 2.30-2.35 (m, 2H),1.93-2.03 (m, 6H), 1.47 (s, 6H), 1.28 (s, 12H). LCMS: Anal. Calcd. forC₃₆H₄₄N₆O₄: 624. found: 625 (M+H)⁺.

Intermediate (9) was dissolved in CH₂Cl₂ (2 mL) and TFA (2 mL) andallowed to stir at room temperature for 1 hour. The solvents wereremoved in vacuo and the crude residue was purified by preparative HPLC(CH₃CN:H₂O:TFA) to give the TFA salt of4,4′-bis(3-((S)-pyrrolidin-2-yl)-1H-pyrazol-5-yl)biphenyl 9a (0.08 g,26%) as a white solid. ¹H NMR (400 MHz, CD₃OD) δ 7.81 (A of app AB q,J=8.5 Hz, 4H), 7.78 (B of app AB q, J=8.5 Hz, 4H), 6.80 (s, 2H), 4.78(dd, (app t) J=7.3, 8.1 Hz, 2H), 3.40-3.51 (m, 4H), 2.47-2.55 (m, 2H),2.14 (m, 6H). LCMS: Anal. Calcd. for C₂₈H₂₈N₆: 424. found: 425 (M+H)⁺.

Preparation of Intermediate 16: (S)-tert-butyl2-(5-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-4H-1,2,4-triazol-3-yl)pyrrolidine-1-carboxylate

Step 1: Anhydrous HCl gas was bubbled through a solution of4-iodobenzonitrile 12 (2.22 g, 9.74 mmol) in dry methanol (80 mL) at 0°C. for 40 minutes and the mixture was then allowed to stir for 48 hours.The solvent was removed in vacuo (the vessel was back-filled with Ar toavoid introduction of moisture) and the residue was dissolved in drymethanol (40 mL). This solution was then added to a solution ofhydrazine hydrate (55% w/w aqueous solution, 3.0 mL, 33.9 mmol) at roomtemperature and the mixture was stirred for 1 hour before the solventwas removed in vacuo. The residue was triturated with dry THF and themixture was filtered to remove insoluble salts. The resulting THFsolution of 4-iodobenzimidohydrazide (13) was used directly in the nextstep.

Step 2: To a solution of(S)-1-(tert-butoxycarbonyl)pyrrolidine-2-carboxylic acid (14) (1.81 g,8.39 mmol) in THF (30 mL) cooled to −10° C. under Ar was added NEt₃ (1.2mL, 8.6 mmol) and then isobutylchloroformate (1.1 mL, 8.5 mmol). Themixture was allowed to stir for 20 minutes at −10° C. and then filteredunder Ar while cold. To the resultant solution was added dropwise theTHF solution of 4-iodobenzimidohydrazide prepared in the previous step.The reaction mixture was allowed to stir for 2 hours and then thesolvent was removed in vacuo. Approximately half of the crude material(ca. 4.19 mmol) was taken up in xylene (40 mL) and the mixture wasplaced in an oil-bath pre-heated to 185° C. After 30 minutes thereaction mixture was cooled, the solvent was removed in vacuo and theresidue was purified by column chromatography (hexane:ethyl acetate,2:1) and then crystallized (hexane-ethyl acetate) to give (S)-tert-butyl2-(5-(4-iodophenyl)-4H-1,2,4-triazol-3-yl)pyrrolidine-1-carboxylate as acolorless solid (15) (0.438 g, 24%). ¹H NMR (400 MHz, DMSO-d₆) δ 13.91(s, 1H), 7.74-7.88 (m, 4H), 4.84-4.93 (m, 1H), 3.51-3.55 (m, 1H),3.33-3.37 (m, 1H, partially obscured by H₂O peak), 2.21-2.32 (m, 1H),1.87-1.91 (m, 3H), 1.38 (s, 4H), 1.13 (s, 5H). LCMS: Anal. Calcd. forC₁₇H₂₁N₄O₂: 440. found: 441 (M+H)⁺.

Step 3: A mixture of (S)-tert-butyl2-(5-(4-iodophenyl)-4H-1,2,4-triazol-3-yl)pyrrolidine-1-carboxylate (15)(0.210 g, 0.476 mmol), bis(pinacolato)diboron (0.261 g, 1.03 mmol), KOAc(0.136 g, 1.39 mmol) and Pd(PPh₃)₄ (0.025 g, 0.0217 mmol) in dioxane (5mL) was degassed with a stream of Ar for 15 minutes. The mixture wasthen heated at 85° C. for 12 hours, at which time it was charged with afurther 0.130 g (0.5 mmol) of bis(pinacolato)diboron and 0.012 g (0.011mmol) of Pd(PPh₃)₄ and heated for another 36 hours. The cooled mixturewas poured into ethyl acetate/H₂O and the layers were separated. Theaqueous phase was re-extracted with ethyl acetate (2×) and the combinedorganic layers were washed (H₂O, brine) and dried (Na₂SO₄) and filtered.The solvent was removed in vacuo and the residue purified by flashchromatography (hexane:ethyl acetate, 1:1) to afford (S)-tert-butyl2-(5-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-4H-1,2,4-triazol-3-yl)pyrrolidine-1-carboxylate(16) (0.161 g, 77%). as a colorless solid. ¹H NMR suggested that thematerial was contaminated with ca. 5-10% of bis(pinacolato)diboron, butit was used as such in subsequent steps. ¹H NMR (400 MHz, DMSO-d₆) δ14.23 (s, 0.3H), 13.92 (s, 0.7H), 7.99 (A of app AB quartet, d, J=7.4Hz, 2H), 7.73 (B of app AB quartet, d, J=7.4 Hz, 4H), 4.81-4.93 (m, 1H),3.53 (s, br, 1H), 3.35-3.39 (m, 1H), 1.38 (s, 3H), 1.30 (s, 12H), 1.13(s, 6H). LCMS: Anal. Calcd. for C₂₃H₃₃BN₄O₄: 440. found: 441 (M+H)⁺.

Preparation of Intermediate 19: (S)-tert-butyl2-(5-(4′-(2-((S)-1-(tert-butoxycarbonyl)pyrrolidin-2-yl)-1H-imidazol-5-yl)biphenyl-4-yl)-1H-pyrazol-3-yl)pyrrolidine-1-carboxylate

General Method A: A mixture of (S)-tert-butyl2-(5-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1H-imidazol-2-yl)pyrrolidine-1-carboxylate(17) (Scheme 9; 0.138 g, 0.314 mmol), (S)-tert-butyl2-(5-(4-iodophenyl)-1H-pyrazol-3-yl)pyrrolidine-1-carboxylate 8 (0.141g, 0.321 mmol), NaHCO₃ (0.110 g, 1.31 mmol) and Pd(PPh₃)₄ (0.024 g,0.0208 mmol) in a mixture of DME (3 mL) and H₂O (1 mL) was heated at 80°C. under Ar for 12 hours. The cooled mixture was diluted with ethylacetate/H₂O, the layers separated and the aqueous phase was re-extractedwith ethyl acetate (2×). The combined organic layers were washed (H₂O,brine) and dried (Na₂SO₄) and filtered and the solvent was removed invacuo. The resulting residue was purified by flash chromatography(hexane:ethyl acetate, 2:1 and then ethyl acetate:methanol, 9:1) to give(S)-tert-butyl2-(5-(4′-(2-((S)-1-(tert-butoxycarbonyl)pyrrolidin-2-yl)-1H-imidazol-5-yl)biphenyl-4-yl)-1H-pyrazol-3-yl)pyrrolidine-1-carboxylate(19) (0.084 g, 43%) as a yellow solid. ¹H NMR (400 MHz, DMSO-d₆) δ13.01, 12.69, 12.20, 11.91, 11.85 (s, 1H), 7.63-7.85 (m, 8H), 7.50-7.56(m, 1H), 6.52 (s, 1H), 4.75-4.94 (m, 2H), 3.42-3.58 (m, 2H), 3.30-3.39(m, 2H, partially obscured by H₂O signal), 2.10-2.28 (m, 2H), 1.81-2.01(m, 6H), 1.40 (s, 7H), 1.20-1.23 (m, 6H), 1.13-1.15 (m, 5H). LCMS: Anal.Calcd. for C₃₆H₄₄N₆O₄: 624. found: 625 (M+H)⁺.

The following intermediates were also prepared using General Method Aabove:

Intermediate Structure LCMS 20

Colorless solid (0.046 g, 16%) LCMS: Anal. Calcd. for C₃₄H₄₂N₈O₄: 626;found: 627 (M + H)⁺. 21

Colorless solid (0.038 g, 4%) LCMS: Anal. Calcd. for C₃₅H₄₃N₇O₄: 625;found: 626 (M + H)⁺.

Preparation of Intermediate 26:(S)-4-(5-(1-(tert-butoxycarbonyl)pyrrolidin-2-yl)-1,3,4-oxadiazol-2-yl)phenylboronicacid

Step 1: To a solution of 4-iodobenzoylhydrazide (22) (1.20 g, 4.58mmol), (S)-1-(tert-butoxycarbonyl)pyrrolidine-2-carboxylic acid (14)(1.03 g, 4.79 mmol) and i-Pr₂NEt (2.0 mL, 11.2 mmol) in DMF (75 mL) wasadded 3-(diethoxyphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one (DEPBT)(2.00 g, 6.68 mol) portionwise. The reaction mixture was stirred at roomtemperature for 2 hours and then it was poured into H₂O/ethyl acetate.The layers were separated. The aqueous phase was extracted with ethylacetate (2×) and the combined organic layers were washed (H₂O, brine)and dried (Na₂SO₄) and filtered. The solvent was removed in vacuo andthe residue purified by flash chromatography (hexane:ethyl acetate, 1:1)to afford the diacylhydrazide (23) as a colorless foam (1.99 g, 99%). ¹HNMR (400 MHz, DMSO-d₆) δ 10.52 (s, 0.5H), 10.39 (s, 0.5H), 9.94 (d,J=7.9 Hz, 1H), 7.88 (app dd, J=8.5, 5.2 Hz, 2H), 7.64 (app d, J=8.5 Hz,2H), 4.18 (unresolved ddd, 1H), 3.37-3.43 (m, 1H), 3.24-3.29 (m, 1H),2.10-2.17 (m, 1H), 1.75-1.96 (m, 3H), 1.38 (s, 4.5H), 1.37 (s, 4.5H).LCMS: Anal. Calcd. for C₁₇H₂₂IN₃O₄: 459. found: 460 (M+H)⁺.

Step 2: To a suspension of the diacylhydrazide (23) prepared in theprevious step, PPh₃ (1.71 g, 6.54 mmol) and i-Pr₂NEt (2.30 mL, 12.97mmol) in CH₃CN (50 mL) at room temperature was added hexachloroethane(1.41 g, 5.97 mmol). The reaction was stirred at room temperature for1.5 hours and then the solvent was removed in vacuo and the residue waspartitioned with ethyl acetate/H₂O. The layers were separated, theaqueous phase was re-extracted with ethyl acetate (2×) and the combinedorganic layers were washed (H₂O, brine) and dried (Na₂SO₄). The solventwas removed in vacuo and the residue was purified by columnchromatography (hexane:ethyl acetate, 3:1) to give (S)-tert-butyl2-(5-(4-iodophenyl)-1,3,4-oxadiazol-2-yl)pyrrolidine-1-carboxylate 24(1.89 g, 99%) as a colorless oil. ¹H NMR (400 MHz, DMSO-d₆) δ 7.98 (A ofapp AB quartet, d, J=8.4 Hz, 2H), 7.74 (A of app AB quartet, d, J=8.4Hz, 2H), 5.02-5.06 (m, 1H), 3.47-3.53 (m, 1H), 3.36-3.41 (m, 1H),2.26-2.32 (m, 1H), 1.91-2.09 (m, 3H), 1.37 (s, 4H), 1.17 (s, 5H). LCMS:Anal. Calcd. for C₁₇H₂₀IN₃O₃: 441. found: 442 (M+H)⁺.

Step 3: A mixture of (S)-tert-butyl2-(5-(4-iodophenyl)-1,3,4-oxadiazol-2-yl)pyrrolidine-1-carboxylate (24)(0.574 g, 1.30 mmol), bis(pinacolato)diboron (0.665 g, 2.62 mmol), KOAc(0.641 g, 6.53 mmol) and Pd(PPh₃)₄ (0.076 g, 0.0658 mmol) in dioxane (5mL) was degassed with a stream of Ar for 15 minutes. The mixture wasthen heated at 100° C. for 12 hours, cooled to room temperature andpoured into ethyl acetate/H₂O. The layers were separated, the aqueousphase was re-extracted with ethyl acetate (2×) and the combined organiclayers were washed (H₂O, brine) and dried (Na₂SO₄) and filtered. Thesolvent was removed in vacuo and the residue purified by flashchromatography (hexane:ethyl acetate, 1:1) to give a mixture of thetitle boronate ester (25) and boronic acid (26). This mixture wasrepurified by prep HPLC (CH₃CN:H₂O:TFA) to afford(S)-4-(5-(1-(tert-butoxycarbonyl)pyrrolidin-2-yl)-1,3,4-oxadiazol-2-yl)phenylboronicacid 26 as a colorless solid (0.101 g, 22%). ¹HNMR (400 MHz, DMSO-d₆) δ8.31 (s, br, 2H), 7.94-8.00 (m, 4H), 5.03-5.10 (m, 1H), 3.37-3.42 (m,2H), 2.31-2.40 (m, 1H), 1.92-2.04 (m, 3H). 1.38 (s, 3H), 1.18 (s, 6H);LCMS: Anal. Calcd. for C₁₇H₂₂BN₃O₅: 359. found: 360 (M+H)⁺.

Preparation of Intermediate 29: (S)-tert-Butyl2-(5-(4′-(5-((S)-1-(tert-butoxycarbonyl)pyrrolidin-2-yl)-1,3,4-oxadiazol-2-yl)biphenyl-4-yl)-1H-imidazol-2-yl)pyrrolidine-1-carboxylate

A mixture(S)-4-(5-(1-(tert-butoxycarbonyl)pyrrolidin-2-yl)-1,3,4-oxadiazol-2-yl)phenylboronicacid (27) (0.090 g, 0.251 mmol), (S)-tert-butyl2-(5-(4-bromophenyl)-1H-imidazol-2-yl)pyrrolidine-1-carboxylate (28)(Scheme 9; 0.098 g, 0.250 mmol), NaHCO₃ (0.076 g, 0.906 mmol) andPd(PPh₃)₄ (0.019 g, 0.016 mmol) in a mixture of DME (3 mL) and H₂O (1mL) was degassed with a stream of Ar for 15 minutes and the mixture wasthen heated at 80° C. for 12 hours. The cooled mixture was diluted withethyl acetate/H₂O, the layers were separated and the aqueous phase wasre-extracted with ethyl acetate (2×). The combined organic layers werewashed (H₂O, brine) and dried (Na₂SO₄) and filtered, and the solvent wasremoved in vacuo. Purification of the residue by prep HPLC(CH₃CN:H₂O:NH₄OAc) gave the title compound 29 (0.045 g, 29%) as a lightyellow glass. LCMS: Anal. Calcd. for C₃₅H₄₂N₆O₅: 626. found: 627 (M+H)⁺.

Preparation of Example 30:Dimethyl-(1R,1′R)-2,2′-((2S,2′S)-2,2′-(5,5′-(biphenyl-4,4′-diyl)bis(1H-pyrazole-5,3-diyl))bis(pyrrolidine-2,1-diyl))bis(2-oxo-1-phenylethane-2,1-diyl)dicarbamate

General Method B: A solution of (2S,2′S)-tert-butyl2,2′-(5,5′-(biphenyl-4,4′-diyl)bis(1H-pyrazole-5,3-diyl))dipyrrolidine-1-carboxylate(9) (0.080 g, 0.12 mmol) in CH₂Cl₂ (2.5 mL) was treated with TFA (2.5mL). The mixture was stirred at room temperature for 1 hour and then thesolvents were removed in vacuo. The residue was purified by prep HPLC(CH₃CN:H₂O:TFA) to afford the TFA salt of4,4′-bis(3-((S)-pyrrolidin-2-yl)-1H-pyrazol-5-yl)biphenyl (9a) as acolorless solid (0.080 g, 19%).

¹H NMR (400 MHz, CD₃OD) δ 7.81 (A of app AB quartet, d, J=8.6 Hz, 4H)7.78 (B of app AB quartet, d, J=8.6 Hz, 4H), 6.80 (s, 2H), 4.78 (app t,J=7.3, 8.1 Hz, 2H), 3.41-3.50 (m, 4H), 2.48-2.55 (m, 2H), 2.14-2.37 (m,6H). LCMS: Anal. Calcd. for C₂₆H₂₈N₆: 424. found: 425 (M+H)⁺.

To a solution of the TFA salt of4,4′-bis(3-((S)-pyrrolidin-2-yl)-1H-pyrazol-5-yl)biphenyl (9a) (0.040 g,0.0613 mmol), (R)-2-(methoxycarbonylamino)-2-phenylacetic acid cap-4(0.033 g, 0.158 mmol) and HATU (0.061 g, 0.160 mmol) in DMF (2 mL) atroom temperature was added i-Pr₂NEt (0.21 mL, 1.23 mmol). The mixturewas allowed to stir at room temperature for 4 hours and then the crudereaction mixture was directly purified by preparative HPLC(CH₃CN:H₂O:TFA) and then repurified by preparative HPLC(CH₃CN:H₂O:NH₄OAc) to give the title compound (30) (0.014 g, 29%) as awhite fluffy solid. ¹H NMR (400 MHz, DMSO-d₆) δ 13.05-13.30 (m, 1H),12.63-12.85 (m, 1H), 7.73-7.81 (m, 9H), 7.30-7.43 (m, 8H), 7.03 (s, br,1H), 6.93 (m, 0.7H), 6.76 (s, 0.3H), 6.62 (s, 0.7H), 6.43 (s, 0.3H),5.87 (s, 0.5H), 5.44-5.49 (m, 2H), 5.31 (s, br, 0.5H), 5.05-5.18 (m,1.7H), 4.71-4.73 (m, 0.3H), 3.91 (s, 1H), 3.71-3.75 (m, 1H), 3.55 (s,3H), 3.53 (s, 3H), 3.53 (m, obscured, 1H), 3.18 (s, 1H), 1.88-2.01 (m,8H).

LCMS: Anal. Calcd. for C₄₆H₄₆N₈O₆: 809. found: 810 (M+H)⁺.

The following examples were also prepared using General Method B and theappropriate carboxylic acid:

Ex- am- ple Structure LCMS (31)

TFA salt, colorless powder, (0.018 g, 27%) LCMS: Anal. Calcd. forC₄₆H₄₆N₈O₆: 806; found: 807 (M + H)⁺. (32)

TFA salt, colorless powder (0.011 g, 14%) LCMS: Anal. Calcd. forC₄₆H₅₀N₈O₂: 746; found: 747 (M + H)⁺. (33)

Colorless powder (0.015 g, 32%) LCMS: Anal. Calcd. for C₄₅H₄₅N₉O₆: 807;found: 808 (M + H)⁺. (34)

TFA salt, colorless solid, (0.069 g, 27%) LCMS: Anal. Calcd. forC₄₄H₄₄N₁₀O₈: 808; found: 809 (M + H)⁺. (35)

TFA salt, colorless solid, (0.055 g, 33%) LCMS: Anal. Calcd. forC₄₄H₄₈N₁₀O₂: 748; found: 749 (M + H)⁺. (36)

LCMS: Anal. Calcd. for C₄₅H₄₄N₈O₇: 808; found: 809 (M + H)⁺.

Preparation of Intermediate 17: (S)-tert-butyl2-(5-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1H-imidazol-2-yl)pyrrolidine-1-carboxylate

Step 1: N,N-Diisopropylethylamine (18 mL, 103.3 mmol) was addeddropwise, over 15 minutes, to a heterogeneous mixture of N-Boc-L-proline14 (7.139 g, 33.17 mmol), HATU (13.324 g, 35.04 mmol), the HCl salt of2-amino-1-(4-bromophenyl)ethanone (8.127 g, 32.44 mmol), and DMF (105mL), and stirred at ambient condition for 55 minutes. Most of thevolatile component was removed in vacuo, and the resulting residue waspartitioned between ethyl acetate (300 mL) and water (200 mL). Theorganic layer was washed with water (200 mL) and brine, dried (MgSO₄),filtered, and concentrated in vacuo. A silica gel mesh was prepared fromthe residue and submitted to flash chromatography (silica gel; 50-60%ethyl acetate/hexanes) to provide ketoamide (36) as a white solid (12.8g). ¹H NMR (DMSO-d₆, δ=2.5 ppm, 400 MHz): δ 8.25-8.14 (m, 1H), 7.92 (brd, J=8.0, 2H), 7.75 (br d, J=8.6, 2H), 4.61 (dd, J=18.3, 5.7, 1H), 4.53(dd, J=18.1, 5.6, 1H), 4.22-4.12 (m, 1H), 3.43-3.35 (m, 1H), 3.30-3.23(m, 1H), 2.18-2.20 (m, 1H), 1.90-1.70 (m, 3H), 1.40/1.34 (two app br s,9H). LC/MS: Anal. Calcd. for [M+Na]⁺ C₁₈H₂₃BrN₂NaO₄: 433.07. found433.09.

Step 2: A mixture of ketoamide (36) (12.8 g, 31.12 mmol) and NH₄OAc(12.0 g, 155.7 mmol) in xylenes (155 mL) was heated in a sealed tube at140° C. for 2 hours. The volatile component was removed in vacuo, andthe residue was partitioned carefully between ethyl acetate and water,whereby enough saturated NaHCO₃ solution was added so as to make the pHof the aqueous phase slightly basic after the shaking of the biphasicsystem. The layers were separated, and the aqueous layer was extractedwith an additional ethyl acetate. The combined organic phase was washedwith brine, dried (MgSO₄), filtered, and concentrated in vacuo. Theresulting material was recrystallized from ethyl acetate/hexanes toprovide two crops of imidazole (28) as a light-yellow dense solid,weighing 5.85 g. The mother liquor was concentrated in vacuo andsubmitted to a flash chromatography (silica gel; 30% ethylacetate/hexanes) to provide an additional 2.23 g of imidazole (28). ¹HNMR (DMSO-d₆, δ=2.5 ppm, 400 MHz): δ 12.17/11.92/11.86 (m, 1H),7.72-7.46/7.28 (m, 5H), 4.86-4.70 (m, 1H), 3.52 (app br s, 1H), 3.36 (m,1H), 2.30-1.75 (m, 4H), 1.40/1.15 (app br s, 9H). LC/MS: Anal. Calcd.for [M+H]⁺ C₁₈H₂₃BrN₃O₂: 392.10. found 391.96; HRMS: Anal. Calcd. for[M+H]⁺ C₁₈H₂₃BrN₃O₂: 392.0974. found 392.0959.

The optical purity of the two samples of (28) were assessed using thechiral HPLC conditions noted below (ee>99% for the combined crops;ee=96.7% for the sample from flash chromatography):

Column: Chiralpak AD, 10 um, 4.6×50 mm

Solvent: 2% ethanol/heptane (isocratic)

Flow rate: 1 mL/min

Wavelength: either 220 or 254 nm

Relative retention time: 2.83 minutes (R), 5.34 minutes (S)

Step 3: Pd(Ph₃P)₄ (469 mg, 0.406 mmol) was added to a pressure tubecontaining a mixture of bromide (28) (4.008 g, 10.22 mmol),bis(pinacolato)diboron (5.422 g, 21.35 mmol), potassium acetate (2.573g, 26.21 mmol) and 1,4-dioxane (80 mL). The reaction flask was purgedwith nitrogen, capped and heated with an oil bath at 80° C. for 16.5hours. The reaction mixture was filtered and the filtrate wasconcentrated in vacuo. The crude material was partitioned carefullybetween CH₂Cl₂ (150 mL) and an aqueous medium (50 mL water+10 mLsaturated NaHCO₃ solution). The aqueous layer was extracted with CH₂Cl₂,and the combined organic phase was dried (MgSO₄), filtered, andconcentrated in vacuo. The resulting material was purified with flashchromatography (sample was loaded with eluting solvent; 20-35% ethylacetate/CH₂Cl₂) to provide boronate (17), contaminated with pinacol, asan off-white dense solid; the relative mole ratio of (17) to pinacol wasabout 10:1 (¹H NMR). The sample weighed 3.925 g after ˜2.5 days exposureto high vacuum. ¹H NMR (DMSO-d₆, δ=2.5 ppm, 400 MHz): 12.22/11.94/11.87(m, 1H), 7.79-7.50/7.34-7.27 (m, 5H), 4.86-4.70 (m, 1H), 3.52 (app br s,1H), 3.36 (m, 1H), 2.27-1.77 (m, 4H), 1.45-1.10 (m, 21H). LC/MS: Anal.Calcd. for [M+H]⁺ C₂₄H₃₅BN₃O₄: 440.27. found 440.23.

Preparation of Example 37 Step 1: Preparation of(S)-tert-butyl2-(2-(4-bromophenyl)-2-oxoethylcarbamoyl)pyrrolidine-1-carboxylate

To a solution of 2-amino-1-(4-bromophenyl)ethanone hydrochloride salt(1.10 g, 4.39 mmol), (S)-1-(tert-butoxycarbonyl)pyrrolidine-2-carboxylicacid (1.02 g, 4.73 mmol), and diisopropylethylamine (3.10 mL, 17.4 mmol)in DMF (20 mL) was added3-(diethoxyphosphoryloxy)-(1,2,3)-benzotriazin-4(3H)-one (DEPBT, 2.0 g,6.68 mmol) and the solution was allowed to stir for 2 hours. The mixturewas poured into H₂O-ethyl acetate and the layers were separated. Theaqueous phase was extracted twice with ethyl acetate and the combinedorganic layers were washed (H₂O×2, brine), dried (Na₂SO₄), and filtered.The solvent was removed in vacuo and the residue purified by flashcolumn chromatography (1:1 hexanes:ethyl acetate) to provide(S)-tert-butyl2-(2-(4-bromophenyl)-2-oxoethylcarbamoyl)pyrrolidine-1-carboxylate (1.02g, 56%) as a colorless foam. ¹HNMR (400 MHz, DMSO-d₆) δ 8.16-8.21 (m,1H), 7.90-7.92 (m, 2H), 7.73-7.75 (m, 2H), 4.59 (dd, J=5.7, 18.4 Hz,1H), 4.51 (dd, J=5.7, 18.4 Hz, 1H), 4.13-4.19 (m, 1H), 3.24-3.27 (m, 2H,partially obscured by H₂O), 2.05-2.12 (m, 1H), 1.74-1.81 (m, 3H), 1.39(s, 3H), 1.33 (3, 6H); LCMS: Anal. Calcd. for C₁₈H₂₃BrN₂O₄: 410. found:411 (M+H)⁺.

Step 2: Preparation of (S)-tert-butyl2-(5-(4-bromophenyl)oxazol-2-yl)pyrrolidine-1-carboxylate

To a solution of the product of Step 1 (1.00 g, 2.43 mmol), PPh₃ (1.00g, 3.71 mmol) and diisopropylethylamine (1.3 mL, 7.28 mmol) in CH₃CN (30mL) was added hexachloroethane (0.812 g, 3.43 mmol) as a solid,portion-wise. The mixture was allowed to stir for 12 hours. TLC (3:1hexanes:ethyl acetate) indicated the presence of starting material.Therefore, additional PPh₃ (0.65 g, 2.43 mmol) and hexachloroethane(0.575 g, 2.43 mmol) were added and stirring continued for 4 hours. Thesolvent was removed in vacuo, the residue diluted with ethyl acetate-H₂Oand the layers separated. The aqueous phase was extracted twice withethyl acetate and the combined organic layers were washed (H₂O, brine),dried (Na₂SO₄), and filtered. The solvent was removed in vacuo and theresidue purified by flash column chromatography (3:1 hexanes:ethylacetate) to provide (S)-tert-butyl2-(5-(4-bromophenyl)oxazol-2-yl)pyrrolidine-1-carboxylate (0.605 g,63%). ¹HNMR (400 MHz, DMSO-d₆) δ 7.60-7.68 (m, 5H), 4.80-4.91 (m, 1H),3.46-3.51 (m, 1H), 3.33-3.39 (m, 1H), 2.18-2.31 (m, 1H), 1.84-1.99 (m,3H), 1.36 (s, 4H), 1.15 (s, 5H). LCMS: Anal. Calcd. for C₁₈H₂₁BrN₂O₃:392. found: 393 (M+H)⁺.

Step 3: Preparation of (S)-tert-butyl2-(5-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)oxazol-2-yl)pyrrolidine-1-carboxylate

A mixture of the product of Step 2 (0.60 g, 1.53 mmol),bis(pinacolato)diboron (0.98 g, 3.84 mmol), KOAc (0.54 g, 5.48 mmol) andPd(PPh₃)₄ (0.10 g, 0.087 mmol) in dioxane (20 ml) was heated at 100° C.for 12 hours. The mixture was poured into H₂O-ethyl acetate and thelayers separated. The aqueous phase was extracted twice with ethylacetate and the combined organic layers were washed (H₂O, brine), dried(Na₂SO₄), and filtered. The solvent was removed in vacuo and the residuepurified by flash column chromatography (2:1 hexanes:ethyl acetate) toafford (S)-tert-butyl2-(5-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)oxazol-2-yl)pyrrolidine-1-carboxylateas a light orange oil (742 mg, >100%) which ¹H NMR showed to becontaminated with approximately 5-10% triphenylphosphine oxide. Thematerial was used as is in subsequent steps. LCMS: Anal. Calcd. forC₂₄H₃₃BN₂O₅: 440. found: 441 (M+H)⁺.

Step 4: Preparation of (S)-tert-butyl2-(5-(4′-(5-((S)-1-(tert-butoxycarbonyl)pyrrolidin-2-yl)-1H-imidazol-2-yl)biphenyl-4-yl)oxazol-2-yl)pyrrolidine-1-carboxylate

A mixture of the product of Step 3 (0.72 g, 1.63 mmol), the product ofStep 2 (0.64 g, 1.63 mmol), Pd(PPh₃)₄ (0.094 g, 0.08 mmol), and NaHCO₃(0.41 g, 4.89 mmol) in DME:H₂O (3:1, 20 mL) was heated at 90° C. for 12hours. The mixture was poured into H₂O-ethyl acetate and the layersseparated. The aqueous phase was extracted twice with ethyl acetate andthe combined organic layers were washed (H₂O, brine), dried (Na₂SO₄),and filtered. The solvent was removed in vacuo and the residue purifiedby flash column chromatography (4:1 hexanes:ethyl acetate then ethylacetate) to provide (S)-tert-butyl2-(5-(4′-(5-((S)-1-(tert-butoxycarbonyl)pyrrolidin-2-yl)-1H-imidazol-2-yl)biphenyl-4-yl)oxazol-2-yl)pyrrolidine-1-carboxylateas a light yellow glass (431 mg, 42%). ¹HNMR (400 MHz, DMSO-d₆) δ11.85-12.21 (m, 1H), 7.66-7.84 (m, 9H), 7.01-7.84 (m, 1H), 4.74-5.05 (m,2H), 3.48-3.54 (m, 2H), 3.35-3.40 (m, 2H), 2.13-2.34 (m, 2H), 1.82-2.02(m, 6H), 1.39 (s, 6H), 1.18 (s, 6H), 1.16 (s, 3H), 1.14 (s, 3H) LCMS:Anal. Calcd. for C₃₆H₄₃N₅O₅: 625. found: 626 (M+H)⁺.

Step 5: Preparation of2-((S)-pyrrolidin-2-yl)-5-(4′-(5-((S)-pyrrolidin-2-yl)-1H-imidazol-2-yl)biphenyl-4-yl)oxazole

To (S)-tert-butyl2-(5-(4′-(2-((S)-1-(tert-butoxycarbonyl)pyrrolidin-2-yl)-1H-imidazol-5-yl)biphenyl-4-yl)oxazol-2-yl)pyrrolidine-1-carboxylate(313 mg, 0.500 mmol) in 5 mL methanol was added HCl/dioxane (5 ml, 20.00mmol) at ambient temperature. After 30 minutes the solution becameyellow and heterogenous. After 2 hours, analysis by LC/MS indicated thereaction was complete. The reaction mixture was diluted with 20 mLdiethyl ether and filtered providing a light orange solid which wasdried under high vacuum to afford 240 mg of the desired product as thetris-HCl salt. ¹H NMR (500 MHz, DMSO-d₆) δ ppm 1.93-2.23 (m, 5H)2.26-2.47 (m, 6H) 2.63 (s, 1H) 4.81-4.92 (m, 1H) 4.97 (t, J=6.56 Hz, 1H)7.77-8.01 (m, 10H) LCMS: Anal. Calcd. for C₃₆H₄₃N₅O₅: 426. found: 427(M+H)⁺.

Step 6: Preparation of Example 37

To a solution of the product of Step 5 (50 mg, 0.93 mmol) and Cap-51(36.0 mg, 0.21 mmol) in DMF (1.5 mL) was added diisopropylethylamine (98μl, 0.56 mmol) followed by HATU (78 mg, 0.206 mmol). After 16 hours, thereaction mixture was concentrated and purified via preparative HPLC. Thefraction containing the desired peak as assayed by LC/MS was passedthrough an Oasis MCX cartridge (preconditioned with methanol), washedwith methanol, and eluted with NH₃/methanol. Concentration in vacuoafforded 75 mg of Example 37 as a colorless foam. ¹H NMR (500 MHz,DMSO-d₆) δ ppm 0.75-1.01 (m, 12H) 1.76-2.32 (m, 10H) 3.54 (s, 6H)3.73-3.93 (m, 4H) 4.00-4.14 (m, J=9.16 Hz, 2H) 5.00-5.21 (m, 2H)7.22-7.42 (m, J=43.03 Hz, 2H) 7.46-7.96 (m, 10H). LC/MS: Anal. Calcd.For C₄₀H₄₉N₇O₇: 740. found: 741 (M+H)⁺.

Example 38 was prepared in similar fashion starting with2-((S)-pyrrolidin-2-yl)-5-(4′-(5-((S)-pyrrolidin-2-yl)-1H-imidazol-2-yl)biphenyl-4-yl)oxazoleand Cap 52.

¹H NMR (500 MHz, DMSO-d₆) δ ppm 1.03-1.16 (m, 6H) 1.90-2.32 (m, 8H)3.16-3.21 (m, 3H) 3.23 (s, 3H) 3.38-3.52 (m, 3H) 3.79-3.93 (m, 4H)4.24-4.37 (m, 2H) 5.07 (dd, J=7.17, 3.51 Hz, 1H) 5.15 (dd, J=8.09, 3.51Hz, 1H) 7.24-7.30 (m, 1H) 7.36 (d, J=7.63 Hz, 1H) 7.54 (d, J=1.53 Hz,1H) 7.60-7.64 (m, 1H) 7.67-7.76 (m, 4H) 7.75-7.87 (m, 4H). LC/MS: Anal.Calcd. For C₄₀H₄₉N₇O₉: 772. found: 773 (M+H)⁺.

LC Conditions (Unless Otherwise Noted)

Condition I

Column=Phenomenex-Luna 3.0×50 mm S10

Start % B=0

Final % B=100

Gradient time=2 min

Stop time=3 min

Flow Rate=4 mL/min

Wavelength=220 nm

Solvent A=0.1% TFA in 10% methanol/90% H₂O

Solvent B=0.1% TFA in 90% methanol/10% H₂O

Condition II

Column=Phenomenex-Luna 4.6×50 mm S10

Start % B=0

Final % B=100

Gradient time=2 min

Stop time=3 min

Flow Rate=5 mL/min

Wavelength=220 nm

Solvent A=0.1% TFA in 10% methanol/90% H₂O

Solvent B=0.1% TFA in 90% methanol/10% H₂O

Condition III

Column ═HPLC XTERRA C18 3.0×50 mm S7

Start % B=0

Final % B=100

Gradient time=3 min

Stop time=4 min

Flow Rate=4 mL/min

Wavelength=220 nm

Solvent A=0.1% TFA in 10% methanol/90% H₂O

Solvent B=0.1% TFA in 90% methanol/10% H₂O

Synthesis of Common Pyrrolidine Caps

A suspension of 10% Pd/C (2.0 g) in methanol (10 mL) was added to amixture of (R)-2-phenylglycine (10 g, 66.2 mmol), formaldehyde (33 mL of37% wt. in water), 1N HCl (30 mL) and methanol (30 mL), and exposed toH₂ (60 psi) for 3 hours. The reaction mixture was filtered throughdiatomaceous earth (Celite™), and the filtrate was concentrated invacuo. The resulting crude material was recrystallized from isopropanolto provide the HCl salt of Cap-1 as a white needle (4.0 g). Opticalrotation: −117.1° [c=9.95 mg/mL in H₂O; λ=589 nm]. ¹H NMR (DMSO-d₆,δ=2.5 ppm, 500 MHz): δ 7.43-7.34 (m, 5H), 4.14 (s, 1H), 2.43 (s, 6H); LC(Cond. J): RT=0.25; LC/MS: Anal. Calcd. for [M+H]⁺ C₁₀H₁₄NO₂ 180.10.found 180.17; HRMS: Anal. Calcd. for [M+H]⁺ C₁₀H₁₄NO₂ 180.1025. found180.1017.

NaBH₃CN (6.22 g, 94 mmol) was added in portions over a few minutes to acooled (ice/water) mixture of (R)-2-Phenylglycine (6.02 g, 39.8 mmol)and methanol (100 mL), and stirred for 5 minutes. Acetaldehyde (10 mL)was added dropwise over 10 minutes and stirring was continued at thesame cooled temperature for 45 minutes and at ambient temperature for˜6.5 hours. The reaction mixture was cooled back with ice-water bath,treated with water (3 mL) and then quenched with a dropwise addition ofconcentrated HCl over ˜45 minutes until the pH of the mixture was˜1.5-2.0. The cooling bath was removed and the stirring was continuedwhile adding concentrated HCl in order to maintain the pH of the mixturearound 1.5-2.0. The reaction mixture was stirred overnight, filtered toremove the white suspension, and the filtrate was concentrated in vacuo.The crude material was recrystallized from ethanol to afford the HClsalt of Cap-2 as a shining white solid in two crops (crop-1: 4.16 g;crop-2:2.19 g). ¹H NMR (DMSO-d₆, δ=2.5 ppm, 400 MHz): 10.44 (1.00, br s,1H), 7.66 (m, 2H), 7.51 (m, 3H), 5.30 (s, 1H), 3.15 (br m, 2H), 2.98 (brm, 2H), 1.20 (app br s, 6H). Crop-1: [α]²⁵-102.21° (c=0.357, H₂O);crop-2: [α]²⁵-99.7° (c=0.357, H₂O). LC (Cond. J): RT=0.43 min; LC/MS:Anal. Calcd. for [M+H]⁺ C₁₂H is NO₂: 208.13. found 208.26

Acetaldehyde (5.0 mL, 89.1 mmol) and a suspension of 10% Pd/C (720 mg)in methanol/H₂O (4 mL/1 mL) was sequentially added to a cooled (˜15° C.)mixture of (R)-2-phenylglycine (3.096 g, 20.48 mmol), 1N HCl (30 mL) andmethanol (40 mL). The cooling bath was removed and the reaction mixturewas stirred under a balloon of H₂ for 17 hours. An additionalacetaldehyde (10 mL, 178.2 mmol) was added and stirring continued underH₂ atmosphere for 24 hours [Note: the supply of H₂ was replenished asneeded throughout the reaction]. The reaction mixture was filteredthrough diatomaceous earth (Celite™), and the filtrate was concentratedin vacuo. The resulting crude material was recrystallized fromisopropanol to provide the HCl salt of (R)-2-(ethylamino)-2-phenylaceticacid as a shining white solid (2.846 g). ¹H NMR (DMSO-d₆, δ=2.5 ppm, 400MHz): δ 14.15 (br s, 1H), 9.55 (br s, 2H), 7.55-7.48 (m, 5H), 2.88 (brm, 1H), 2.73 (br m, 1H), 1.20 (app t, J=7.2, 3H). LC (Cond. J): RT=0.39min; >95% homogeneity index; LC/MS: Anal. Calcd. for [M+H]⁺ C₁₀H₁₄NO₂:180.10. found 180.18.

A suspension of 10% Pd/C (536 mg) in methanol/H₂O (3 mL/1 mL) was addedto a mixture of (R)-2-(ethylamino)-2-phenylacetic acid/HCl (1.492 g,6.918 mmol), formaldehyde (20 mL of 37% wt. in water), 1N HCl (20 mL)and methanol (23 mL). The reaction mixture was stirred under a balloonof H₂ for ˜72 hours, where the H₂ supply was replenished as needed. Thereaction mixture was filtered through diatomaceous earth (Celite™) andthe filtrate was concentrated in vacuo. The resulting crude material wasrecrystallized from isopropanol (50 mL) to provide the HCl salt of Cap-3as a white solid (985 mg). ¹H NMR (DMSO-d₆, δ=2.5 ppm, 400 MHz): δ 10.48(br s, 1H), 7.59-7.51 (m, 5H), 5.26 (s, 1H), 3.08 (app br s, 2H), 2.65(br s, 3H), 1.24 (br m, 3H). LC (Cond. J): RT=0.39 min; >95% homogeneityindex; LC/MS: Anal. Calcd. for [M+H]⁺ C₁₁H₁₆NO₂: 194.12. found 194.18;HRMS: Anal. Calcd. for [M+H]⁺ C₁₁H₁₆NO₂: 194.1180. found 194.1181.

ClCO₂Me (3.2 mL, 41.4 mmol) was added dropwise to a cooled (ice/water)THF (410 mL) semi-solution of (R)-tert-butyl 2-amino-2-phenylacetate/HCl(9.877 g, 40.52 mmol) and diisopropylethylamine (14.2 mL, 81.52 mmol)over 6 min, and stirred at similar temperature for 5.5 hours. Thevolatile component was removed in vacuo, and the residue was partitionedbetween water (100 mL) and ethyl acetate (200 mL). The organic layer waswashed with 1N HCl (25 mL) and saturated NaHCO₃ solution (30 mL), dried(MgSO₄), filtered, and concentrated in vacuo. The resultant colorlessoil was triturated from hexanes, filtered and washed with hexanes (100mL) to provide (R)-tert-butyl 2-(methoxycarbonylamino)-2-phenylacetateas a white solid (7.7 g). ¹H NMR (DMSO-d₆, δ=2.5 ppm, 400 MHz): 7.98 (d,J=8.0, 1H), 7.37-7.29 (m, 5H), 5.09 (d, J=8, 1H), 3.56 (s, 3H), 1.33 (s,9H). LC (Cond. J): RT=1.53 min; ˜90% homogeneity index; LC/MS: Anal.Calcd. for [M+Na]⁺ C₁₄H₁₉NNaO₄: 288.12. found 288.15.

TFA (16 mL) was added dropwise to a cooled (ice/water) CH₂Cl₂ (160 mL)solution of the above product over 7 minutes, and the cooling bath wasremoved and the reaction mixture was stirred for 20 hours. Since thedeprotection was still not complete, an additional TFA (1.0 mL) wasadded and stirring continued for an additional 2 hours. The volatilecomponent was removed in vacuo, and the resulting oil residue wastreated with diethyl ether (15 mL) and hexanes (12 mL) to provide aprecipitate. The precipitate was filtered and washed with diethylether/hexanes (˜1:3 ratio; 30 mL) and dried in vacuo to provide Cap-4 asa fluffy white solid (5.57 g). Optical rotation: −176.9° [c=3.7 mg/mL inH₂O; λ=589 nm]. ¹H NMR (DMSO-d₆, δ=2.5 ppm, 400 MHz): δ 12.84 (br s,1H), 7.96 (d, J=8.3, 1H), 7.41-7.29 (m, 5H), 5.14 (d, J=8.3, 1H), 3.55(s, 3H). LC (Cond. J): RT=1.01 min; >95% homogeneity index; LC/MS: Anal.Calcd. for [M+H]⁺ C₁₀H₁₂NO₄ 210.08. found 210.17; HRMS: Anal. Calcd. for[M+H]⁺ C₁₀H₁₂NO₄ 210.0766. found 210.0756.

A mixture of (R)-2-phenylglycine (1.0 g, 6.62 mmol), 1,4-dibromobutane(1.57 g, 7.27 mmol) and Na₂CO₃ (2.10 g, 19.8 mmol) in ethanol (40 mL)was heated at 100° C. for 21 hours. The reaction mixture was cooled toambient temperature and filtered, and the filtrate was concentrated invacuo. The residue was dissolved in ethanol and acidified with 1N HCl topH 3-4, and the volatile component was removed in vacuo. The resultingcrude material was purified by a reverse phase HPLC (water/methanol/TFA)to provide the TFA salt of Cap-5 as a semi-viscous white foam (1.0 g).¹H NMR (DMSO-d₆, δ=2.5, 500 MHz) δ 10.68 (br s, 1H), 7.51 (m, 5H), 5.23(s, 1H), 3.34 (app br s, 2H), 3.05 (app br s, 2H), 1.95 (app br s, 4H);RT=0.30 minutes (Cond. I); >98% homogeneity index; LC/MS: Anal. Calcd.for [M+H]⁺ C₁₂H₁₆NO₂: 206.12. found 206.25.

The TFA salt of Cap-6 was synthesized from (R)-2-phenylglycine and1-bromo-2-(2-bromoethoxy)ethane by using the method of preparation ofCap-5. ¹H NMR (DMSO-d₆, δ=2.5, 500 MHz) δ 12.20 (br s, 1H), 7.50 (m,5H), 4.92 (s, 1H), 3.78 (app br s, 4H), 3.08 (app br s, 2H), 2.81 (appbr s, 2H); RT=0.32 minutes (Cond. I); >98%; LC/MS: Anal. Calcd. for[M+H]⁺ C₁₂H₁₆NO₃: 222.11. found 222.20; HRMS: Anal. Calcd. for [M+H]⁺C₁₂H₁₆NO₃: 222.1130. found 222.1121.

A CH₂Cl₂ (200 mL) solution of p-toluenesulfonyl chloride (8.65 g, 45.4mmol) was added dropwise to a cooled (−5° C.) CH₂Cl₂ (200 mL) solutionof (S)-benzyl 2-hydroxy-2-phenylacetate (10.0 g, 41.3 mmol),triethylamine (5.75 mL, 41.3 mmol) and 4-dimethylaminopyridine (0.504 g,4.13 mmol), while maintaining the temperature between −5° C. and 0° C.The reaction was stirred at 0° C. for 9 hours, and then stored in afreezer (−25° C.) for 14 hours. It was allowed to thaw to ambienttemperature and washed with water (200 mL), 1N HCl (100 mL) and brine(100 mL), dried (MgSO₄), filtered, and concentrated in vacuo to providebenzyl 2-phenyl-2-(tosyloxy)acetate as a viscous oil which solidifiedupon standing (16.5 g). The chiral integrity of the product was notchecked and that product was used for the next step without furtherpurification. ¹H NMR (DMSO-d₆, δ=2.5, 500 MHz) δ 7.78 (d, J=8.6, 2H),7.43-7.29 (m, 10H), 7.20 (m, 2H), 6.12 (s, 1H), 5.16 (d, J=12.5, 1H),5.10 (d, J=12.5, 1H), 2.39 (s, 3H). RT=3.00 (Cond. III); >90%homogeneity index; LC/MS: Anal. Calcd. for [M+H]⁺ C₂₂H₂₀NaO₅S: 419.09.found 419.04.

A THF (75 mL) solution of benzyl 2-phenyl-2-(tosyloxy)acetate (6.0 g,15.1 mmol), 1-methylpiperazine (3.36 mL, 30.3 mmol) andN,N-diisopropylethylamine (13.2 mL, 75.8 mmol) was heated at 65° C. for7 hours. The reaction was allowed to cool to ambient temperature and thevolatile component was removed in vacuo. The residue was partitionedbetween ethylacetate and water, and the organic layer was washed withwater and brine, dried (MgSO₄), filtered, and concentrated in vacuo. Theresulting crude material was purified by flash chromatography (silicagel, ethyl acetate) to provide benzyl2-(4-methylpiperazin-1-yl)-2-phenylacetate as an orangish-brown viscousoil (4.56 g). Chiral HPLC analysis (Chiralcel OD-H) indicated that thesample is a mixture of enantiomers in a 38.2 to 58.7 ratio. Theseparation of the enantiomers were effected as follow: the product wasdissolved in 120 mL of ethanol/heptane (1:1) and injected (5mL/injection) on chiral HPLC column (Chiracel OJ, 5 cm ID×50 cm L, 20μm) eluting with 85:15 Heptane/ethanol at 75 mL/min, and monitored at220 nm. Enantiomer-1 (1.474 g) and enantiomer-2 (2.2149 g) wereretrieved as viscous oil. ¹H NMR (CDCl₃, δ=7.26, 500 MHz) 7.44-7.40 (m,2H), 7.33-7.24 (m, 6H), 7.21-7.16 (m, 2H), 5.13 (d, J=12.5, 1H), 5.08(d, J=12.5, 1H), 4.02 (s, 1H), 2.65-2.38 (app br s, 8H), 2.25 (s, 3H).RT=2.10 (Cond. III); >98% homogeneity index; LC/MS: Anal. Calcd. for[M+H]⁺ C₂₀H₂₅N₂O₂: 325.19. found 325.20.

A methanol (10 mL) solution of either enantiomer of benzyl2-(4-methylpiperazin-1-yl)-2-phenylacetate (1.0 g, 3.1 mmol) was addedto a suspension of 10% Pd/C (120 mg) in methanol (5.0 mL). The reactionmixture was exposed to a balloon of hydrogen, under a carefulmonitoring, for <50 minutes. Immediately after the completion of thereaction, the catalyst was filtered through diatomaceous earth (Celite™)and the filtrate was concentrated in vacuo to provide Cap-7,contaminated with phenylacetic acid as a tan foam (867.6 mg; mass isabove the theoretical yield). The product was used for the next stepwithout further purification. ¹H NMR (DMSO-d₆, δ=2.5, 500 MHz) δ7.44-7.37 (m, 2H), 7.37-7.24 (m, 3H), 3.92 (s, 1H), 2.63-2.48 (app. bs,2H), 2.48-2.32 (m, 6H), 2.19 (s, 3H); RT=0.31 (Cond. II); >90%homogeneity index; LC/MS: Anal. Calcd. for [M+H]⁺ C₁₃H₁₉N₂O₂: 235.14.found 235.15; HRMS: Anal. Calcd. for [M+H]⁺ C₁₃H₁₉N₂O₂: 235.1447. found235.1440.

The synthesis of Cap-8 and Cap-9 was conducted according to thesynthesis of Cap-7 by using appropriate amines for the SN₂ displacementstep (i.e., 4-hydroxypiperidine for Cap-8 and (S)-3-fluoropyrrolidinefor Cap-9) and modified conditions for the separation of the respectivestereoisomeric intermediates, as described below.

The enantiomeric separation of the intermediate benzyl2-(4-hydroxypiperidin-1-yl)-2-phenyl acetate was effected by employingthe following conditions: the compound (500 mg) was dissolved inethanol/heptane (5 mL/45 mL). The resulting solution was injected (5mL/injection) on a chiral HPLC column (Chiracel OJ, 2 cm ID×25 cm L, 10μm) eluting with 80:20 heptane/ethanol at 10 mL/min, monitored at 220nm, to provide 186.3 mg of enantiomer-1 and 209.1 mg of enantiomer-2 aslight-yellow viscous oils. These benzyl ester was hydrogenolyzedaccording to the preparation of Cap-7 to provide Cap-8: ¹H NMR (DMSO-d₆,δ=2.5, 500 MHz) 7.40 (d, J=7, 2H), 7.28-7.20 (m, 3H), 3.78 (s 1H), 3.46(m, 1H), 2.93 (m, 1H), 2.62 (m, 1H), 2.20 (m, 2H), 1.70 (m, 2H), 1.42(m, 2H). RT=0.28 (Cond. II); >98% homogeneity index; LC/MS: Anal. Calcd.for [M+H]⁺ C₁₃H₁₈NO₃: 236.13. found 236.07; HRMS: Calcd. for [M+H]⁺C₁₃H₁₈NO₃: 236.1287. found 236.1283.

The diastereomeric separation of the intermediate benzyl2-((S)-3-fluoropyrrolidin-1-yl)-2-phenylacetate was effected byemploying the following conditions: the ester (220 mg) was separated ona chiral HPLC column (Chiracel OJ-H, 0.46 cm ID×25 cm L, 5 μm) elutingwith 95% CO₂/5% methanol with 0.1% TFA, at 10 bar pressure, 70 mL/minflow rate, and a temperature of 35° C. The HPLC elute for the respectivestereoisomers was concentrated, and the residue was dissolved in CH₂Cl₂(20 mL) and washed with an aqueous medium (10 mL water+1 mL saturatedNaHCO₃ solution). The organic phase was dried (MgSO₄), filtered, andconcentrated in vacuo to provide 92.5 mg of fraction-1 and 59.6 mg offraction-2. These benzyl esters were hydrogenolyzed according to thepreparation of Cap-7 to prepare Caps 9a and 9b. Cap-9a (diastereomer-1;the sample is a TFA salt as a result of purification on a reverse phaseHPLC using H₂O/methanol/TFA solvent): ¹H NMR (DMSO-d₆, δ=2.5, 400 MHz)7.55-7.48 (m, 5H), 5.38 (d of m, J=53.7, 1H), 5.09 (br s, 1H), 3.84-2.82(br m, 4H), 2.31-2.09 (m, 2H). RT=0.42 (Cond. I); >95% homogeneityindex; LC/MS: Anal. Calcd. for [M+H]⁺ C₁₂H₁₅FNO₂: 224.11. found 224.14;Cap-9b (diastereomer-2): ¹H NMR (DMSO-d₆, δ=2.5, 400 MHz) 7.43-7.21 (m,5H), 5.19 (d of m, J=55.9, 1H), 3.97 (s, 1H), 2.95-2.43 (m, 4H),2.19-1.78 (m, 2H). RT=0.44 (Cond. I); LC/MS: Anal. Calcd. for [M+H]⁺C₁₂H₁₅FNO₂: 224.11. found 224.14.

To a solution of D-proline (2.0 g, 17 mmol) and formaldehyde (2.0 mL of37% wt. in H₂O) in methanol (15 mL) was added a suspension of 10% Pd/C(500 mg) in methanol (5 mL). The mixture was stirred under a balloon ofhydrogen for 23 hours. The reaction mixture was filtered throughdiatomaceous earth (Celite™) and concentrated in vacuo to provide Cap-10as an off-white solid (2.15 g). ¹H NMR (DMSO-d₆, δ=2.5, 500 MHz) 3.42(m, 1H), 3.37 (dd, J=9.4, 6.1, 1H), 2.85-2.78 (m, 1H), 2.66 (s, 3H),2.21-2.13 (m, 1H), 1.93-1.84 (m, 2H), 1.75-1.66 (m, 1H). RT=0.28 (Cond.II); >98% homogeneity index; LC/MS: Anal. Calcd. for [M+H]⁺ C₆H₁₂NO₂:130.09. found 129.96.

A mixture of (2S,4R)-4-fluoropyrrolidine-2-carboxylic acid (0.50 g, 3.8mmol), formaldehyde (0.5 mL of 37% wt. in H₂O), 12 N HCl (0.25 mL) and10% Pd/C (50 mg) in methanol (20 mL) was stirred under a balloon ofhydrogen for 19 hours. The reaction mixture was filtered throughdiatomaceous earth (Celite™) and the filtrate was concentrated in vacuo.The residue was recrystallized from isopropanol to provide the HCl saltof Cap-11 as a white solid (337.7 mg). ¹H NMR (DMSO-d₆, δ=2.5, 500 MHz)5.39 (d m, J=53.7, 1H), 4.30 (m, 1H), 3.90 (ddd, J=31.5, 13.5, 4.5, 1H),3.33 (dd, J=25.6, 13.4, 1H), 2.85 (s, 3H), 2.60-2.51 (m, 1H), 2.39-2.26(m, 1H). RT=0.28 (Cond. II); >98% homogeneity index; LC/MS: Anal. Calcd.for [M+H]⁺ C₆H₁₁FNO₂: 148.08. found 148.06.

L-Alanine (2.0 g, 22.5 mmol) was dissolved in 10% aqueous sodiumcarbonate solution (50 mL), and a THF (50 mL) solution of methylchloroformate (4.0 mL) was added to it. The reaction mixture was stirredunder ambient conditions for 4.5 hours and concentrated in vacuo. Theresulting white solid was dissolved in water and acidified with 1N HClto a pH˜2-3. The resulting solutions was extracted with ethyl acetate(3×100 mL), and the combined organic phase was dried (Na₂SO₄), filtered,and concentrated in vacuo to provide a colorless oil (2.58 g). 500 mg ofthis material was purified by a reverse phase HPLC (H₂O/methanol/TFA) toprovide 150 mg of Cap-12 as a colorless oil. ¹HNMR (DMSO-d₆, δ=2.5, 500MHz) 7.44 (d, J=7.3, 0.8H), 7.10 (br s, 0.2H), 3.97 (m, 1H), 3.53 (s,3H), 1.25 (d, J=7.3, 3H).

A mixture of L-alanine (2.5 g, 28 mmol), formaldehyde (8.4 g, 37 wt. %),1N HCl (30 mL) and 10% Pd/C (500 mg) in methanol (30 mL) was stirredunder a hydrogen atmosphere (50 psi) for 5 hours. The reaction mixturewas filtered through diatomaceous earth (Celite™) and the filtrate wasconcentrated in vacuo to provide the HCl salt of Cap-13 as an oil whichsolidified upon standing under vacuum (4.4 g; the mass is abovetheoretical yield). The product was used without further purification.¹H NMR (DMSO-d₆, δ=2.5, 500 MHz) δ 12.1 (br s, 1H), 4.06 (q, J=7.4, 1H),2.76 (s, 6H), 1.46 (d, J=7.3, 3H).

Step 1: A mixture of (R)-(−)-D-phenylglycine tert-butyl ester (3.00 g,12.3 mmol), NaBH₃CN (0.773 g, 12.3 mmol), KOH (0.690 g, 12.3 mmol) andacetic acid (0.352 mL, 6.15 mmol) were stirred in methanol at 0° C. Tothis mixture was added glutaric dialdehyde (2.23 mL, 12.3 mmol) dropwiseover 5 minutes. The reaction mixture was stirred as it was allowed towarm to ambient temperature and stirring was continued at the sametemperature for 16 hours. The solvent was subsequently removed and theresidue was partitioned with 10% aqueous NaOH and ethyl acetate. Theorganic phase was separated, dried (MgSO₄), filtered and concentrated todryness to provide a clear oil. This material was purified byreverse-phase preparative HPLC (Primesphere C-18, 30×100 mm;CH₃CN—H₂O-0.1% TFA) to give the intermediate ester (2.70 g, 56%) as aclear oil. ¹H NMR (400 MHz, CDCl₃) δ 7.53-7.44 (m, 3H), 7.40-7.37 (m,2H), 3.87 (d, J=10.9 Hz, 1H), 3.59 (d, J=10.9 Hz, 1H), 2.99 (t, J=11.2Hz, 1H), 2.59 (t, J=11.4 Hz, 1H), 2.07-2.02 (m, 2H), 1.82 (d, J=1.82 Hz,3H), 1.40 (s, 9H). LC/MS: Anal. Calcd. for C₁₇H₂₅NO₂: 275. found: 276(M+H)⁺.

Step 2: To a stirred solution of the intermediate ester (1.12 g, 2.88mmol) in dichloromethane (10 mL) was added TFA (3 mL). The reactionmixture was stirred at ambient temperature for 4 hours and then it wasconcentrated to dryness to give a light yellow oil. The oil was purifiedusing reverse-phase preparative HPLC (Primesphere C-18, 30×100 mm;CH₃CN—H₂O-0.1% TFA). The appropriate fractions were combined andconcentrated to dryness in vacuo. The residue was then dissolved in aminimum amount of methanol and applied to applied to MCX LP extractioncartridges (2×6 g). The cartridges were rinsed with methanol (40 mL) andthen the desired compound was eluted using 2M ammonia in methanol (50mL). Product-containing fractions were combined and concentrated and theresidue was taken up in water. Lyophilization of this solution providedthe title compound (0.492 g, 78%) as a light yellow solid. ¹H NMR(DMSO-d₆) δ 7.50 (s, 5H), 5.13 (s, 1H), 3.09 (br s, 2H), 2.92-2.89 (m,2H), 1.74 (m, 4H), 1.48 (br s, 2H). LC/MS: Anal. Calcd. for C₁₃H₁₇NO₂:219. found: 220 (M+H)⁺.

Step 1: (S)-1-Phenylethyl 2-bromo-2-phenylacetate: To a mixture ofα-bromophenylacetic acid (10.75 g, 0.050 mol), (S)-(−)-1-phenylethanol(7.94 g, 0.065 mol) and DMAP (0.61 g, 5.0 mmol) in dry dichloromethane(100 mL) was added solid EDCI (12.46 g, 0.065 mol) all at once. Theresulting solution was stirred at room temperature under Ar for 18 hoursand then it was diluted with ethyl acetate, washed (H₂O×2, brine), dried(Na₂SO₄), filtered, and concentrated to give a pale yellow oil. Flashchromatography (SiO₂/hexane-ethyl acetate, 4:1) of this oil provided thetitle compound (11.64 g, 73%) as a white solid. ¹H NMR (400 MHz, CDCl₃)δ 7.53-7.17 (m, 10H), 5.95 (q, J=6.6 Hz, 0.5H), 5.94 (q, J=6.6 Hz,0.5H), 5.41 (s, 0.5H), 5.39 (s, 0.5H), 1.58 (d, J=6.6 Hz, 1.5H), 1.51(d, J=6.6 Hz, 1.5H).

Step 2:(S)-1-Phenylethyl(R)-2-(4-hydroxy-4-methylpiperidin-1-yl)-2-phenylacetate:To a solution of (S)-1-phenylethyl 2-bromo-2-phenylacetate (0.464 g,1.45 mmol) in THF (8 mL) was added triethylamine (0.61 mL, 4.35 mmol),followed by tetrabutylammonium iodide (0.215 g, 0.58 mmol). The reactionmixture was stirred at room temperature for 5 minutes and then asolution of 4-methyl-4-hydroxypiperidine (0.251 g, 2.18 mmol) in THF (2mL) was added. The mixture was stirred for 1 hour at room temperatureand then it was heated at 55-60° C. (oil bath temperature) for 4 hours.The cooled reaction mixture was then diluted with ethyl acetate (30 mL),washed (H₂O×2, brine), dried (MgSO₄), filtered and concentrated. Theresidue was purified by silica gel chromatography (0-60% ethylacetate-hexane) to provide first the (S,R)-isomer of the title compound(0.306 g, 60%) as a white solid and then the corresponding (S,S)-isomer(0.120 g, 23%), also as a white solid. (S,R)-isomer: ¹H NMR (CD₃OD) δ7.51-7.45 (m, 2H), 7.41-7.25 (m, 8H), 5.85 (q, J=6.6 Hz, 1H), 4.05 (s,1H), 2.56-2.45 (m, 2H), 2.41-2.29 (m, 2H), 1.71-1.49 (m, 4H), 1.38 (d,J=6.6 Hz, 3H), 1.18 (s, 3H). LCMS: Anal. Calcd. for C₂₂H₂₇NO₃: 353.found: 354 (M+H)⁺. (S,S)-isomer: ¹H NMR (CD₃OD) δ 7.41-7.30 (m, 5H),7.20-7.14 (m, 3H), 7.06-7.00 (m, 2H), 5.85 (q, J=6.6 Hz, 1H), 4.06 (s,1H), 2.70-2.60 (m, 1H), 2.51 (dt, J=6.6, 3.3 Hz, 1H), 2.44-2.31 (m, 2H),1.75-1.65 (m, 1H), 1.65-1.54 (m, 3H), 1.50 (d, J=6.8 Hz, 3H), 1.20 (s,3H). LCMS: Anal. Calcd. for C₂₂H₂₇NO₃: 353. found: 354 (M+H)⁺.

Step 3: (R)-2-(4-Hydroxy-4-methylpiperidin-1-yl)-2-phenylacetic acid: Toa solution of(S)-1-phenylethyl(R)-2-(4-hydroxy-4-methylpiperidin-1-yl)-2-phenylacetate(0.185 g, 0.52 mmol) in dichloromethane (3 mL) was added trifluoroaceticacid (1 mL) and the mixture was stirred at room temperature for 2 hours.The volatiles were subsequently removed in vacuo and the residue waspurified by reverse-phase preparative HPLC (Primesphere C-18, 20×100 mm;CH₃CN—H₂O-0.1% TFA) to give the title compound (as TFA salt) as a palebluish solid (0.128 g, 98%). LCMS: Anal. Calcd. for C₁₄H₁₉NO₃: 249.found: 250 (M+H)⁺.

Step 1: (S)-1-Phenylethyl 2-(2-fluorophenyl)acetate: A mixture of2-fluorophenylacetic acid (5.45 g, 35.4 mmol), (S)-1-phenylethanol (5.62g, 46.0 mmol), EDCI (8.82 g, 46.0 mmol) and DMAP (0.561 g, 4.60 mmol) inCH₂Cl₂ (100 mL) was stirred at room temperature for 12 hours. Thesolvent was then concentrated and the residue partitioned with H₂O-ethylacetate. The phases were separated and the aqueous layer back-extractedwith ethyl acetate (2×). The combined organic phases were washed (H₂O,brine), dried (Na₂SO₄), filtered, and concentrated in vacuo. The residuewas purified by silica gel chromatography (Biotage/0-20% ethylacetate-hexane) to provide the title compound as a colorless oil (8.38g, 92%). ¹H NMR (400 MHz, CD₃OD) δ 7.32-7.23 (m, 7H), 7.10-7.04 (m, 2),5.85 (q, J=6.5 Hz, 1H), 3.71 (s, 2H), 1.48 (d, J=6.5 Hz, 3H).

Step 2: (R)—((S)-1-Phenylethyl)2-(2-fluorophenyl)-2-(piperidin-1-yl)acetate: To a solution of(S)-1-phenylethyl 2-(2-fluorophenyl)acetate (5.00 g, 19.4 mmol) in THF(1200 mL) at 0° C. was added DBU (6.19 g, 40.7 mmol) and the solutionwas allowed to warm to room temperature while stirring for 30 minutes.The solution was then cooled to −78° C. and a solution of CBr₄ (13.5 g,40.7 mmol) in THF (100 mL) was added and the mixture was allowed to warmto −10° C. and stirred at this temperature for 2 hours. The reactionmixture was quenched with saturated aq. NH₄Cl and the layers wereseparated. The aqueous layer was back-extracted with ethyl acetate (2×)and the combined organic phases were washed (H₂O, brine), dried(Na₂SO₄), filtered, and concentrated in vacuo. To the residue was addedpiperidine (5.73 mL, 58.1 mmol) and the solution was stirred at roomtemperature for 24 hours. The volatiles were then concentrated in vacuoand the residue was purified by silica gel chromatography (Biotage/0-30%diethyl ether-hexane) to provide a pure mixture of diastereomers (2:1ratio by ¹H NMR) as a yellow oil (2.07 g, 31%), along with unreactedstarting material (2.53 g, 51%). Further chromatography of thediastereomeric mixture (Biotage/0-10% diethyl ether-toluene) providedthe title compound as a colorless oil (0.737 g, 11%). ¹H NMR (400 MHz,CD₃OD) δ 7.52 (ddd, J=9.4, 7.6, 1.8 Hz, 1H), 7.33-7.40 (m, 1), 7.23-7.23(m, 4H), 7.02-7.23 (m, 4H), 5.86 (q, J=6.6 Hz, 1H), 4.45 (s, 1H),2.39-2.45 (m, 4H), 1.52-1.58 (m, 4H), 1.40-1.42 (m, 1H), 1.38 (d, J=6.6Hz, 3H). LCMS: Anal. Calcd. for C₂₁H₂₄FNO₂: 341. found: 342 (M+H)⁺.

Step 3: (R)-2-(2-fluorophenyl)-2-(piperidin-1-yl)acetic acid: A mixtureof (R)—((S)-1-phenylethyl) 2-(2-fluorophenyl)-2-(piperidin-1-yl)acetate(0.737 g, 2.16 mmol) and 20% Pd(OH)₂/C (0.070 g) in ethanol (30 mL) washydrogenated at room temperature and atmospheric pressure (H₂ balloon)for 2 hours. The solution was then purged with Ar, filtered throughdiatomaceous earth (Celite™), and concentrated in vacuo. This providedthe title compound as a colorless solid (0.503 g, 98%). ¹H NMR (400 MHz,CD₃OD) δ 7.65 (ddd, J=9.1, 7.6, 1.5 Hz, 1H), 7.47-7.53 (m, 1H),7.21-7.30 (m, 2H), 3.07-3.13 (m, 4H), 1.84 (br s, 4H), 1.62 (br s, 2H).LCMS: Anal. Calcd. for C₁₃H₁₆FNO₂: 237. found: 238 (M+H)⁺.

Step 1:(S)-1-Phenylethyl(R)-2-(4-hydroxy-4-phenylpiperidin-1-yl)-2-phenylacetate:To a solution of (S)-1-phenylethyl 2-bromo-2-phenylacetate (1.50 g, 4.70mmol) in THF (25 mL) was added triethylamine (1.31 mL, 9.42 mmol),followed by tetrabutylammonium iodide (0.347 g, 0.94 mmol). The reactionmixture was stirred at room temperature for 5 minutes and then asolution of 4-phenyl-4-hydroxypiperidine (1.00 g, 5.64 mmol) in THF (5mL) was added. The mixture was stirred for 16 hours and then it wasdiluted with ethyl acetate (100 mL), washed (H₂O×2, brine), dried(MgSO₄), filtered and concentrated. The residue was purified on a silicagel column (0-60% ethyl acetate-hexane) to provide an approximately 2:1mixture of diastereomers, as judged by ¹H NMR. Separation of theseisomers was performed using supercritical fluid chromatography(Chiralcel OJ-H, 30×250 mm; 20% ethanol in CO₂ at 35° C.), to give firstthe (R)-isomer of the title compound (0.534 g, 27%) as a yellow oil andthen the corresponding (S)-isomer (0.271 g, 14%), also as a yellow oil.(S,R)-isomer: ¹H NMR (400 MHz, CD₃OD) δ 7.55-7.47 (m, 4H), 7.44-7.25 (m,10H), 7.25-7.17 (m, 1H), 5.88 (q, J=6.6 Hz, 1H), 4.12 (s, 1H), 2.82-2.72(m, 1H), 2.64 (dt, J=11.1, 2.5 Hz, 1H), 2.58-2.52 (m, 1H), 2.40 (dt,J=11.1, 2.5 Hz, 1H), 2.20 (dt, J=12.1, 4.6 Hz, 1H), 2.10 (dt, J=12.1,4.6 Hz, 1H), 1.72-1.57 (m, 2H), 1.53 (d, J=6.5 Hz, 3H). LCMS: Anal.Calcd. for C₂₇H₂₉NO₃: 415. found: 416 (M+H)⁺; (S,S)-isomer: H¹NMR (400MHz, CD₃OD) δ 7.55-7.48 (m, 2H), 7.45-7.39 (m, 2H), 7.38-7.30 (m, 5H),7.25-7.13 (m, 4H), 7.08-7.00 (m, 2H), 5.88 (q, J=6.6 Hz, 1H), 4.12 (s,1H), 2.95-2.85 (m, 1H), 2.68 (dt, J=11.1, 2.5 Hz, 1H), 2.57-2.52 (m,1H), 2.42 (dt, J=11.1, 2.5 Hz, 1H), 2.25 (dt, J=12.1, 4.6 Hz, 1H), 2.12(dt, J=12.1, 4.6 Hz, 1H), 1.73 (dd, J=13.6, 3.0 Hz, 1H), 1.64 (dd,J=13.6, 3.0 Hz, 1H), 1.40 (d, J=6.6 Hz, 3H). LCMS: Anal. Calcd. forC₂₇H₂₉NO₃: 415. found: 416 (M+H)⁺.

The following esters were prepared in similar fashion:

Intermediate-17a

Diastereomer 1: ¹H NMR (500 MHz, DMSO-d₆) δ ppm 1.36 (d, J = 6.41 Hz,3H) 2.23-2.51 (m, 4H) 3.35 (s, 4H) 4.25 (s, 1H) 5.05 (s, 2H) 5.82 (d, J= 6.71 Hz, 1H) 7.15-7.52 (m, 15H). LCMS: Anal. Calcd. for: C₂₈H₃₀N₂O₄458.22; Found: 459.44 (M + H)⁺. Diastereomer 2: ¹H NMR (500 MHz,DMSO-d₆) δ ppm 1.45 (d, J = 6.71 Hz, 3H) 2.27-2.44 (m, 4H) 3.39 (s, 4H)4.23 (s, 1H) 5.06 (s, 2H) 5.83 (d, J = 6.71 Hz, 1H) 7.12 (dd, J = 6.41,3.05 Hz, 2H) 7.19-7.27 (m, 3H) 7.27-7.44 (m, 10H). LCMS: Anal. Calcd.for: C₂₈H₃₀N₂O₄ 458.22; Found: 459.44 (M + H)⁺. Intermediate-17b

Diasteromer 1: RT = 11.76 minutes (Cond'n II); LCMS: Anal. Calcd. for:C₂₀H₂₂N₂O₃ 338.16 Found: 339.39 (M + H)⁺; Diastereomer 2: RT = 10.05minutes (Cond'n II); LCMS: Anal. Calcd. for: C₂₀H₂₂N₂O₃338.16; Found:339.39 (M + H)⁺. Intermediate-17c

Diastereomer 1: T_(R) = 4.55 minutes (Cond'n I); LCMS: Anal. Calcd. for:C₂₁H₂₆N₂O₂ 338.20 Found: 339.45 (M + H)⁺; Diastereomer 2: T_(R) = 6.00minutes (Cond'n I); LCMS: Anal. Calcd. for: C₂₁H₂₆N₂O₂ 338.20 Found:339.45 (M + H)⁺. Intermediate-17d

Diastereomer 1: RT = 7.19 minutes (Cond'n I); LCMS: Anal. Calcd. for:C₂₇H₂₉NO₂ 399.22 Found: 400.48 (M + H)⁺; Diastereomer 2: RT = 9.76minutes (Cond'n I); LCMS: Anal. Calcd. for: C₂₇H₂₉NO₂ 399.22 Found:400.48 (M + H)⁺.Chiral SFC Conditions for Determining Retention TimeCondition IColumn: Chiralpak AD-H Column, 4.62×50 mm, 5 μmSolvents: 90% CO2-10% methanol with 0.1% DEATemp: 35° C.Pressure: 150 barFlow rate: 2.0 mL/min.UV monitored (220 nmInjection: 1.0 mg/3 mL methanolCondition IIColumn: Chiralcel OD-H Column, 4.62×50 mm, 5 μmSolvents: 90% CO2-10% methanol with 0.1% DEATemp: 35° C.Pressure: 150 barFlow rate: 2.0 mL/min.UV monitored @220 nmInjection: 1.0 mg/mL methanol

Cap 17, Step 2; (R)-2-(4-Hydroxy-4-phenylpiperidin-1-yl)-2-phenylaceticacid: To a solution of(S)-1-phenylethyl(R)-2-(4-hydroxy-4-phenylpiperidin-1-yl)-2-phenylacetate(0.350 g, 0.84 mmol) in dichloromethane (5 mL) was added trifluoroaceticacid (1 mL) and the mixture was stirred at room temperature for 2 hours.The volatiles were subsequently removed in vacuo and the residue waspurified by reverse-phase preparative HPLC (Primesphere C-18, 20×100 mm;CH₃CN—H₂O-0.1% TFA) to give the title compound (as TFA salt) as a whitesolid (0.230 g, 88%). LCMS: Anal. Calcd. for C₁₉H₂₁NO₃: 311.15. found:312 (M+H)⁺.

The following carboxylic acids were prepared in optically pure form in asimilar fashion:

Cap- 17a

RT = 2.21 (Cond'n II); ¹H NMR (500 MHz, DMSO-d₆) δ ppm 2.20-2.35 (m, 2H)2.34-2.47 (m, 2H) 3.37 (s, 4H) 3.71 (s, 1H) 5.06 (s, 2H) 7.06-7.53 (m,10H). LCMS: Anal. Calcd. for: C₂₀H₂₂N₂O₄ 354.16; Found: 355.38 (M + H)⁺.Cap- 17b

RT = 0.27 (Cond'n III); LCMS: Anal. Calcd. for: C₁₂H₁₄N₂O₃ 234.10;Found: 235.22 (M + H)⁺. Cap- 17c

RT = 0.48 (Cond'n II); LCMS: Anal. Calcd. for: C₁₃H₁₈N₂O₂ 234.14; Found:235.31 (M + H)⁺. Cap- 17d

RT = 2.21 (Cond'n I); LCMS: Anal. Calcd. for: C₁₉H₂₁NO₂ 295.16; Found:296.33 (M + H)⁺.LCMS Conditions for Determining Retention TimeCondition IColumn: Phenomenex-Luna 4.6×50 mm S10Start % B=0Final % B=100Gradient Time=4 minFlow Rate=4 mL/minWavelength=220Solvent A=10% methanol-90% H₂O-0.1% TFASolvent B=90% methanol-10% H₂O-0.1% TFACondition IIColumn: Waters-Sunfire 4.6×50 mm S5Start % B=0Final % B=100Gradient Time=2 minFlow Rate=4 mL/minWavelength=220Solvent A=10% methanol-90% H₂O-0.1% TFASolvent B=90% methanol-10% H₂O-0.1% TFACondition IIIColumn: Phenomenex 10μ 3.0×50 mmStart % B=0Final % B=100Gradient Time=2 minFlow Rate=4 mL/minWavelength=220Solvent A=10% methanol-90% H₂O-0.1% TFASolvent B=90% methanol-10% H₂O-0.1% TFA

Step 1; (R,S)-Ethyl 2-(4-pyridyl)-2-bromoacetate: To a solution of ethyl4-pyridylacetate (1.00 g, 6.05 mmol) in dry THF (150 mL) at 0° C. underargon was added DBU (0.99 mL, 6.66 mmol). The reaction mixture wasallowed to warm to room temperature over 30 minutes and then it wascooled to −78° C. To this mixture was added CBr₄ (2.21 g, 6.66 mmol) andstirring was continued at −78° C. for 2 hours. The reaction mixture wasthen quenched with sat. aq. NH₄Cl and the phases were separated. Theorganic phase was washed (brine), dried (Na₂SO₄), filtered, andconcentrated in vacuo. The resulting yellow oil was immediately purifiedby flash chromatography (SiO₂/hexane-ethyl acetate, 1:1) to provide thetitle compound (1.40 g, 95%) as a somewhat unstable yellow oil. ¹H NMR(400 MHz, CDCl₃) δ 8.62 (dd, J=4.6, 1.8 Hz, 2H), 7.45 (dd, J=4.6, 1.8Hz, 2H), 5.24 (s, 1H), 4.21-4.29 (m, 2H), 1.28 (t, J=7.1 Hz, 3H). LCMS:Anal. Calcd. for C₉H₁₀BrNO₂: 242, 244. found: 243, 245 (M+H)⁺.

Step 2; (R,S)-Ethyl 2-(4-pyridyl)-2-(N,N-dimethylamino)acetate: To asolution of (R,S)-ethyl 2-(4-pyridyl)-2-bromoacetate (1.40 g, 8.48 mmol)in DMF (10 mL) at room temperature was added dimethylamine (2M in THF,8.5 mL, 17.0 mmol). After completion of the reaction (as judged by thinlayer chromatography) the volatiles were removed in vacuo and theresidue was purified by flash chromatography (Biotage, 40+M SiO₂ column;50%-100% ethyl acetate-hexane) to provide the title compound (0.539 g,31%) as a light yellow oil. ¹H NMR (400 MHz, CDCl₃) δ 8.58 (d, J=6.0 Hz,2H), 7.36 (d, J=6.0 Hz, 2H), 4.17 (m, 2H), 3.92 (s, 1H), 2.27 (s, 6H),1.22 (t, J=7.0 Hz). LCMS: Anal. Calcd. for C₁₁H₁₆N₂O₂: 208. found: 209(M+H)⁺.

Step 3; (R,S)-2-(4-Pyridyl)-2-(N,N-dimethylamino)acetic acid: To asolution of (R,S)-ethyl 2-(4-pyridyl)-2-(N,N-dimethylamino)acetate(0.200 g, 0.960 mmol) in a mixture of THF-methanol-H₂O (1:1:1, 6 mL) wasadded powdered LiOH (0.120 g, 4.99 mmol) at room temperature. Thesolution was stirred for 3 hours and then it was acidified to pH 6 using1N HCl. The aqueous phase was washed with ethyl acetate and then it waslyophilized to give the dihydrochloride of the title compound as ayellow solid (containing LiCl). The product was used as such insubsequent steps. ¹H NMR (400 MHz, DMSO-d₆) δ 8.49 (d, J=5.7 Hz, 2H),7.34 (d, J=5.7 Hz, 2H), 3.56 (s, 1H), 2.21 (s, 6H).

The following examples were prepared in similar fashion using the methoddescribed above;

Cap-19

LCMS: Anal. Calcd. for C₉H₁₂N₂O₂: 180; found: 181 (M + H)⁺. Cap-20

LCMS: no ionization. ¹H NMR (400 MHz, CD₃OD) δ 8.55 (d, J = 4.3 Hz, 1H),7.84 (app t, J = 5.3 Hz, 1H), 7.61 (d, J = 7.8 Hz, 1H), 7.37 (app t, J =5.3 Hz, 1H), 4.35 (s, 1H), 2.60 (s, 6H). Cap-21

LCMS: Anal. Calcd. for C₉H₁₁ClN₂O₂: 214, 216; found: 215, 217 (M + H)⁺.Cap-22

LCMS: Anal. Calcd. for C₁₀H₁₂N₂O₄: 224; found: 225 (M + H)⁺. Cap-23

LCMS: Anal. Calcd. for C₁₄H₁₅NO₂: 229; found: 230 (M + H)⁺. Cap-24

LCMS: Anal. Calcd. for C₁₁H₁₂F₃NO₂: 247; found: 248 (M + H)⁺. Cap-25

LCMS: Anal. Calcd. for C₁₁H₁₂F₃NO₂: 247; found: 248 (M + H)⁺. Cap-26

LCMS: Anal. Calcd. for C₁₀H₁₂FNO₂: 197; found: 198 (M + H)⁺. Cap-27

LCMS: Anal. Calcd. for C₁₀H₁₂FNO₂: 247; found: 248 (M + H)⁺. Cap-28

LCMS: Anal. Calcd. for C₁₀H₁₂ClNO₂: 213; found: 214 (M + H)⁺. Cap-29

LCMS: Anal. Calcd. for C₁₀H₁₂ClNO₂: 213; found: 214 (M + H)⁺. Cap-30

LCMS: Anal. Calcd. for C₁₀H₁₂ClNO₂: 213; found: 214 (M + H)⁺. Cap-31

LCMS: Anal. Calcd. for C₈H₁₂N₂O₂S: 200; found: 201 (M + H)⁺. Cap-32

LCMS: Anal. Calcd. for C₈H₁₁NO₂S: 185; found: 186 (M + H)⁺. Cap-33

LCMS: Anal. Calcd. for C₈H₁₁NO₂S: 185; found: 186 (M + H)⁺. Cap-34

LCMS: Anal. Calcd. for C₁₁H₁₂N₂O₃: 220; found: 221 (M + H)⁺. Cap-35

LCMS: Anal. Calcd. for C₁₂H₁₃NO₂S: 235; found: 236 (M + H)⁺. Cap-36

LCMS: Anal. Calcd. for C₁₂H₁₄N₂O₂S: 250; found: 251 (M + H)⁺. Cap-37

Step 1; (R,S)-Ethyl 2-(quinolin-3-yl)-2-(N,N-dimethylamino)-acetate: Amixture of ethyl N,N-dimethylaminoacetate (0.462 g, 3.54 mmol), K₃PO₄(1.90 g, 8.95 mmol), Pd(t-Bu₃P)₂ (0.090 g, 0.176 mmol) and toluene (10mL) was degassed with a stream of Ar bubbles for 15 minutes. Thereaction mixture was then heated at 100° C. for 12 hours, after which itwas cooled to room temperature and poured into H₂O. The mixture wasextracted with ethyl acetate (2×) and the combined organic phases werewashed (H₂O, brine), dried (Na₂SO₄), filtered, and concentrated invacuo. The residue was purified first by reverse-phase preparative HPLC(Primesphere C-18, 30×100 mm; CH₃CN—H₂O-5 mM NH₄OAc) and then by flashchromatography (SiO₂/hexane-ethyl acetate, 1:1) to provide the titlecompound (0.128 g, 17%) as an orange oil. ¹H NMR (400 MHz, CDCl₃) δ 8.90(d, J=2.0 Hz, 1H), 8.32 (d, J=2.0 Hz, 1H), 8.03-8.01 (m, 2H), 7.77 (ddd,J=8.3, 6.8, 1.5 Hz, 1H), 7.62 (ddd, J=8.3, 6.8, 1.5 Hz, 1H), 4.35 (s,1H), 4.13 (m, 2H), 2.22 (s, 6H), 1.15 (t, J=7.0 Hz, 3H). LCMS: Anal.Calcd. for C₁₅H₁₈N₂O₂: 258. found: 259 (M+H)⁺.

Step 2; (R,S) 2-(Quinolin-3-yl)-2-(N,N-dimethylamino)acetic acid: Amixture of (R,S)-ethyl 2-(quinolin-3-yl)-2-(N,N-dimethylamino)acetate(0.122 g, 0.472 mmol) and 6M HCl (3 mL) was heated at 100° C. for 12hours. The solvent was removed in vacuo to provide the dihydrochlorideof the title compound (0.169 g, >100%) as a light yellow foam. Theunpurified material was used in subsequent steps without furtherpurification. LCMS: Anal. Calcd. for C₁₃H₁₄N₂O₂: 230. found: 231 (M+H)⁺.

Step 1; (R)—((S)-1-phenylethyl)2-(dimethylamino)-2-(2-fluorophenyl)acetate and (S)—((S)-1-phenylethyl)2-(dimethylamino)-2-(2-fluorophenyl)acetate: To a mixture of(RS)-2-(dimethylamino)-2-(2-fluorophenyl)acetic acid (2.60 g, 13.19mmol), DMAP (0.209 g, 1.71 mmol) and (S)-1-phenylethanol (2.09 g, 17.15mmol) in CH₂Cl₂ (40 mL) was added EDCI (3.29 g, 17.15 mmol) and themixture was allowed to stir at room temperature for 12 hours. Thesolvent was then removed in vacuo and the residue partitioned with ethylacetate-H₂O. The layers were separated, the aqueous layer wasback-extracted with ethyl acetate (2×) and the combined organic phaseswere washed (H₂O, brine), dried (Na₂SO₄), filtered, and concentrated invacuo. The residue was purified by silica gel chromatography(Biotage/0-50% diethyl ether-hexane). The resulting pure diastereomericmixture was then separated by reverse-phase preparative HPLC(Primesphere C-18, 30×100 mm; CH₃CN—H₂O-0.1% TFA) to give first(S)-1-phenethyl(R)-2-(dimethylamino)-2-(2-fluorophenyl)acetate (0.501 g,13%) and then(S)-1-phenethyl(S)-2-(dimethylamino)-2-(2-fluorophenyl)-acetate (0.727g. 18%), both as their TFA salts. (S,R)-isomer: ¹H NMR (400 MHz, CD₃OD)δ 7.65-7.70 (m, 1H), 7.55-7.60 (ddd, J=9.4, 8.1, 1.5 Hz, 1H), 7.36-7.41(m, 2H), 7.28-7.34 (m, 5H), 6.04 (q, J=6.5 Hz, 1H), 5.60 (s, 1H), 2.84(s, 6H), 1.43 (d, J=6.5 Hz, 3H). LCMS: Anal. Calcd. for C₁₈H₂₀FNO₂: 301.found: 302 (M+H)⁺; (S,S)-isomer: ¹H NMR (400 MHz, CD₃OD) δ 7.58-7.63 (m,1H), 7.18-7.31 (m, 6H), 7.00 (dd, J=8.5, 1.5 Hz, 2H), 6.02 (q, J=6.5 Hz,1H), 5.60 (s, 1H), 2.88 (s, 6H), 1.54 (d, J=6.5 Hz, 3H). LCMS: Anal.Calcd. for C₁₈H₂₀FNO₂: 301. found: 302 (M+H)⁺.

Step 2; (R)-2-(dimethylamino)-2-(2-fluorophenyl)acetic acid: A mixtureof (R)—((S)-1-phenylethyl) 2-(dimethylamino)-2-(2-fluorophenyl)acetateTFA salt (1.25 g, 3.01 mmol) and 20% Pd(OH)₂/C (0.125 g) in ethanol (30mL) was hydrogenated at room temperature and atmospheric pressure (H₂balloon) for 4 hours. The solution was then purged with Ar, filteredthrough diatomaceous earth (Celite™), and concentrated in vacuo. Thisgave the title compound as a colorless solid (0.503 g, 98%). ¹H NMR (400MHz, CD₃OD) δ 7.53-7.63 (m, 2H), 7.33-7.38 (m, 2H), 5.36 (s, 1H), 2.86(s, 6H). LCMS: Anal. Calcd. for C₁₀H₁₂FNO₂: 197. found: 198 (M+H)⁺.

The S-isomer could be obtained from (S)—((S)-1-phenylethyl)2-(dimethylamino)-2-(2-fluorophenyl)acetate TFA salt in similar fashion.

A mixture of (R)-(2-chlorophenyl)glycine (0.300 g, 1.62 mmol),formaldehyde (35% aqueous solution, 0.80 mL, 3.23 mmol) and 20%Pd(OH)₂/C (0.050 g) was hydrogenated at room temperature and atmosphericpressure (H₂ balloon) for 4 hours. The solution was then purged with Ar,filtered through diatomaceous earth (Celite™) and concentrated in vacuo.The residue was purified by reverse-phase preparative HPLC (PrimesphereC-18, 30×100 mm; CH₃CN—H₂O-0.1% TFA) to give the TFA salt of the titlecompound (R)-2-(dimethylamino)-2-(2-chlorophenyl)acetic acid as acolorless oil (0.290 g, 55%). ¹H NMR (400 MHz, CD₃OD) δ 7.59-7.65 (m,2H), 7.45-7.53 (m, 2H), 5.40 (s, 1H), 2.87 (s, 6H). LCMS: Anal. Calcd.for C₁₀H₁₂ClNO₂: 213. found: 214 (M+H)⁺.

To an ice-cold solution of (R)-(2-chlorophenyl)glycine (1.00 g, 5.38mmol) and NaOH (0.862 g, 21.6 mmol) in H₂O (5.5 mL) was added methylchloroformate (1.00 mL, 13.5 mmol) dropwise. The mixture was allowed tostir at 0° C. for 1 hour and then it was acidified by the addition ofconc. HCl (2.5 mL). The mixture was extracted with ethyl acetate (2×)and the combined organic phase was washed (H₂O, brine), dried (Na₂SO₄),filtered, and concentrated in vacuo to give the title compound(R)-2-(methoxycarbonylamino)-2-(2-chlorophenyl)acetic acid as ayellow-orange foam (1.31 g, 96%). ¹H NMR (400 MHz, CD₃OD) δ 7.39-7.43(m, 2H), 7.29-7.31 (m, 2H), 5.69 (s, 1H), 3.65 (s, 3H). LCMS: Anal.Calcd. for C₁₀H₁₀ClNO₄: 243. found: 244 (M+H)⁺.

To a suspension of 2-(2-(chloromethyl)phenyl)acetic acid (2.00 g, 10.8mmol) in THF (20 mL) was added morpholine (1.89 g, 21.7 mmol) and thesolution was stirred at room temperature for 3 hours. The reactionmixture was then diluted with ethyl acetate and extracted with H₂O (2×).The aqueous phase was lyophilized and the residue was purified by silicagel chromatography (Biotage/0-10% methanol-CH₂Cl₂) to give the titlecompound 2-(2-(Morpholinomethyl)phenyl)acetic acid as a colorless solid(2.22 g, 87%). ¹H NMR (400 MHz, CD₃OD) δ 7.37-7.44 (m, 3H), 7.29-7.33(m, 1H), 4.24 (s, 2H), 3.83 (br s, 4H), 3.68 (s, 2H), 3.14 (br s, 4H).LCMS: Anal. Calcd. for C₁₃H₁₇NO₃: 235. found: 236 (M+H)⁺.

The following examples were similarly prepared using the methoddescribed for Cap-41:

Cap-42

LCMS: Anal. Calcd. for C₁₄H₁₉NO₂: 233; found: 234 (M + H)⁺. Cap-43

LCMS: Anal. Calcd. for C₁₃H₁₇NO₂: 219; found: 220 (M + H)⁺. Cap-44

LCMS: Anal. Calcd. for C₁₁H₁₅NO₂: 193; found: 194 (M + H)⁺. Cap-45

LCMS: Anal. Calcd. for C₁₄H₂₀N₂O₂: 248; found: 249 (M + H)⁺. Cap-45a

HMDS (1.85 mL, 8.77 mmol) was added to a suspension of(R)-2-amino-2-phenylacetic acid p-toluenesulfonate (2.83 g, 8.77 mmol)in CH₂Cl₂ (10 mL) and the mixture was stirred at room temperature for 30minutes. Methyl isocyanate (0.5 g, 8.77 mmol) was added in one portionstirring continued for 30 minutes. The reaction was quenched by additionof H₂O (5 mL) and the resulting precipitate was filtered, washed withH₂O and n-hexanes, and dried under vacuum.(R)-2-(3-methylureido)-2-phenylacetic acid (1.5 g; 82%) was recovered asa white solid and it was used without further purification. ¹H NMR (500MHz, DMSO-d₆) δ ppm 2.54 (d, J=4.88 Hz, 3H) 5.17 (d, J=7.93 Hz, 1H) 5.95(q, J=4.48 Hz, 1H) 6.66 (d, J=7.93 Hz, 1H) 7.26-7.38 (m, 5H) 12.67 (s,1H). LCMS: Anal. Calcd. for C₁₀H₁₂N₂O₃ 208.08 found 209.121 (M+H)⁺; HPLCPhenomenex C-18 3.0×46 mm, 0 to 100% B over 2 minutes, 1 minute holdtime, A=90% water, 10% methanol, 0.1% TFA, B=10% water, 90% methanol,0.1% TFA, RT=1.38 min, 90% homogeneity index.

The desired product was prepared according to the method described forCap-45a. ¹H NMR (500 MHz, DMSO-d₆) δ ppm 0.96 (t, J=7.17 Hz, 3H)2.94-3.05 (m, 2H) 5.17 (d, J=7.93 Hz, 1H) 6.05 (t, J=5.19 Hz, 1H) 6.60(d, J=7.63 Hz, 1H) 7.26-7.38 (m, 5H) 12.68 (s, 1H). LCMS: Anal. Calcd.for C₁₁H₁₄N₂O₃ 222.10 found 223.15 (M+H)⁺.

HPLC XTERRA C-18 3.0×506 mm, 0 to 100% B over 2 minutes, 1 minute holdtime, A=90% water, 10% methanol, 0.2% H₃PO₄, B=10% water, 90% methanol,0.2% H₃PO₄, RT=0.87 min, 90% homogeneity index.

Step 1; (R)-tert-butyl 2-(3,3-dimethylureido)-2-phenylacetate: To astirred solution of (R)-tert-butyl-2-amino-2-phenylacetate (1.0 g, 4.10mmol) and Hunig's base (1.79 mL, 10.25 mmol) in DMF (40 mL) was addeddimethylcarbamoyl chloride (0.38 mL, 4.18 mmol) dropwise over 10minutes. After stirring at room temperature for 3 hours, the reactionwas concentrated under reduced pressure and the resulting residue wasdissolved in ethyl acetate. The organic layer was washed with H₂O, 1Naq. HCl and brine, dried (MgSO₄), filtered and concentrated underreduced pressure. (R)-tert-butyl 2-(3,3-dimethylureido)-2-phenylacetatewas obtained as a white solid (0.86 g; 75%) and used without furtherpurification. ¹H NMR (500 MHz, DMSO-d₆) δ ppm 1.33 (s, 9H) 2.82 (s, 6H)5.17 (d, J=7.63 Hz, 1H) 6.55 (d, J=7.32 Hz, 1H) 7.24-7.41 (m, 5H). LCMS:Anal. Calcd. for C₁₅H₂₂N₂O₃ 278.16 found 279.23 (M+H)⁺; HPLC PhenomenexLUNA C-18 4.6×50 mm, 0 to 100% B over 4 minutes, 1 minute hold time,A=90% water, 10% methanol, 0.1% TFA, B=10% water, 90% methanol, 0.1%TFA, RT=2.26 min, 97% homogeneity index.

Step 2; (R)-2-(3,3-dimethylureido)-2-phenylacetic acid: To a stirredsolution of ((R)-tert-butyl 2-(3,3-dimethylureido)-2-phenylacetate (0.86g, 3.10 mmol) in CH₂Cl₂ (250 mL) was added TFA (15 mL) dropwise and theresulting solution was stirred at rt for 3 hours. The desired compoundwas then precipitated out of solution with a mixture of EtOAC:Hexanes(5:20), filtered off and dried under reduced pressure.(R)-2-(3,3-dimethylureido)-2-phenylacetic acid was isolated as a whitesolid (0.59 g, 86%) and used without further purification. ¹H NMR (500MHz, DMSO-d₆) δ ppm 2.82 (s, 6H) 5.22 (d, J=7.32 Hz, 1H) 6.58 (d, J=7.32Hz, 1H) 7.28 (t, J=7.17 Hz, 1H) 7.33 (t, J=7.32 Hz, 2H) 7.38-7.43 (m,2H) 12.65 (s, 1H). LCMS: Anal. Calcd. for C₁₁H₁₄N₂O₃: 222.24. found:223.21 (M+H)⁺. HPLC XTERRA C-18 3.0×50 mm, 0 to 100% B over 2 minutes, 1minute hold time, A=90% water, 10% methanol, 0.2% H₃PO₄, B=10% water,90% methanol, 0.2% H₃PO₄, RT=0.75 min, 93% homogeneity index.

Step 1; (R)-tert-butyl 2-(3-cyclopentylureido)-2-phenylacetate: To astirred solution of (R)-2-amino-2-phenylacetic acid hydrochloride (1.0g, 4.10 mmol) and Hunig's base (1.0 mL, 6.15 mmol) in DMF (15 mL) wasadded cyclopentyl isocyanate (0.46 mL, 4.10 mmol) dropwise and over 10minutes. After stirring at room temperature for 3 hours, the reactionwas concentrated under reduced pressure and the resulting residue wastaken up in ethyl acetate. The organic layer was washed with H₂O andbrine, dried (MgSO₄), filtered, and concentrated under reduced pressure.(R)-tert-butyl 2-(3-cyclopentylureido)-2-phenylacetate was obtained asan opaque oil (1.32 g; 100%) and used without further purification. ¹HNMR (500 MHz, CD₃Cl-D) δ ppm 1.50-1.57 (m, 2H) 1.58-1.66 (m, 2H)1.87-1.97 (m, 2H) 3.89-3.98 (m, 1H) 5.37 (s, 1H) 7.26-7.38 (m, 5H).LCMS: Anal. Calcd. for C₁₈H₂₆N₂O₃ 318.19 found 319.21 (M+H)⁺; HPLCXTERRA C-18 3.0×50 mm, 0 to 100% B over 4 minutes, 1 minute hold time,A=90% water, 10% methanol, 0.1% TFA, B=10% water, 90% methanol, 0.1%TFA, RT=2.82 min, 96% homogeneity index.

Step 2; (R)-2-(3-cyclopentylureido)-2-phenylacetic acid: To a stirredsolution of (R)-tert-butyl 2-(3-cyclopentylureido)-2-phenylacetate (1.31g, 4.10 mmol) in CH₂Cl₂ (25 mL) was added TFA (4 mL) and trietheylsilane(1.64 mL; 10.3 mmol) dropwise, and the resulting solution was stirred atroom temperature for 6 hours. The volatile components were removed underreduced pressure and the crude product was recrystallized in ethylacetate/pentanes to yield (R)-2-(3-cyclopentylureido)-2-phenylaceticacid as a white solid (0.69 g, 64%). ¹H NMR (500 MHz, DMSO-d₆) δ ppm1.17-1.35 (m, 2H) 1.42-1.52 (m, 2H) 1.53-1.64 (m, 2H) 1.67-1.80 (m, 2H)3.75-3.89 (m, 1H) 5.17 (d, J=7.93 Hz, 1H) 6.12 (d, J=7.32 Hz, 1H) 6.48(d, J=7.93 Hz, 1H) 7.24-7.40 (m, 5H) 12.73 (s, 1H). LCMS: Anal. Calcd.for C₁₄H₁₈N₂O₃: 262.31. found: 263.15 (M+H)⁺. HPLC XTERRA C-18 3.0×50mm, 0 to 100% B over 2 minutes, 1 minute hold time, A=90% water, 10%methanol, 0.2% H₃PO₄, B=10% water, 90% methanol, 0.2% H₃PO₄, RT=1.24min, 100% homogeneity index.

To a stirred solution of 2-(benzylamino)acetic acid (2.0 g, 12.1 mmol)in formic acid (91 mL) was added formaldehyde (6.94 mL, 93.2 mmol).After five hours at 70° C., the reaction mixture was concentrated underreduced pressure to 20 mL and a white solid precipitated. Followingfiltration, the mother liquors were collected and further concentratedunder reduced pressure providing the crude product. Purification byreverse-phase preparative HPLC (Xterra 30×100 mm, detection at 220 nm,flow rate 35 mL/min, 0 to 35% B over 8 min; A=90% water, 10% methanol,0.1% TFA, B=10% water, 90% methanol, 0.1% TFA) provided the titlecompound 2-(benzyl(methyl)-amino)acetic acid as its TFA salt (723 mg,33%) as a colorless wax. ¹H NMR (300 MHz, DMSO-d₆) δ ppm 2.75 (s, 3H)4.04 (s, 2H) 4.34 (s, 2H) 7.29-7.68 (m, 5H). LCMS: Anal. Calcd. for:C₁₀H₁₃NO₂ 175.05. Found: 180.20 (M+H)⁺.

To a stirred solution of 3-methyl-2-(methylamino)butanoic acid (0.50 g,3.81 mmol) in water (30 mL) was added K₂CO₃ (2.63 g, 19.1 mmol) andbenzyl chloride (1.32 g, 11.4 mmol). The reaction mixture was stirred atambient temperature for 18 hours. The reaction mixture was extractedwith ethyl acetate (30 mL×2) and the aqueous layer was concentratedunder reduced pressure providing the crude product which was purified byreverse-phase preparative HPLC (Xterra 30×100 mm, detection at 220 nm,flow rate 40 mL/min, 20 to 80% B over 6 min; A=90% water, 10% methanol,0.1% TFA, B=10% water, 90% methanol, 0.1% TFA) to provide2-(benzyl(methyl)amino)-3-methylbutanoic acid, TFA salt (126 mg, 19%) asa colorless wax. ¹H NMR (500 MHz, DMSO-d₆) δ ppm 0.98 (d, 3H) 1.07 (d,3H) 2.33-2.48 (m, 1H) 2.54-2.78 (m, 3H) 3.69 (s, 1H) 4.24 (s, 2H)7.29-7.65 (m, 5H). LCMS: Anal. Calcd. for: C₁₃H₁₉NO₂ 221.14. Found:222.28 (M+H)⁺.

Na₂CO₃ (1.83 g, 17.2 mmol) was added to NaOH (33 mL of 1M/H₂O, 33 mmol)solution of L-valine (3.9 g, 33.29 mmol) and the resulting solution wascooled with ice-water bath. Methyl chloroformate (2.8 mL, 36.1 mmol) wasadded dropwise over 15 min, the cooling bath was removed and thereaction mixture was stirred at ambient temperature for 3.25 hr. Thereaction mixture was washed with ether (50 mL, 3×), and the aqueousphase was cooled with ice-water bath and acidified with concentrated HClto a pH region of 1-2, and extracted with CH₂Cl₂ (50 mL, 3×). Theorganic phase was dried (MgSO₄) and evaporated in vacuo to afford Cap-51as a white solid (6 g). ¹H NMR for the dominant rotamer (DMSO-d₆, δ=2.5ppm, 500 MHz): 12.54 (s, 1H), 7.33 (d, J=8.6, 1H), 3.84 (dd, J=8.4, 6.0,1H), 3.54 (s, 3H), 2.03 (m, 1H), 0.87 (m, 6H). HRMS: Anal. Calcd. for[M+H]⁺ C₇H₁₄NO₄: 176.0923. found 176.0922

Cap-52 was synthesized from L-alanine according to the proceduredescribed for the synthesis of Cap-51. For characterization purposes, aportion of the crude material was purified by a reverse phase HPLC(H₂O/methanol/TFA) to afford Cap-52 as a colorless viscous oil. ¹H NMR(DMSO-d₆, δ=2.5 ppm, 500 MHz): 12.49 (br s, 1H), 7.43 (d, J=7.3, 0.88H),7.09 (app br s, 0.12H), 3.97 (m, 1H), 3.53 (s, 3H), 1.25 (d, J=7.3, 3H).

Cap-53 to -64 were prepared from appropriate starting materialsaccording to the procedure described for the synthesis of Cap-51, withnoted modifications if any.

Cap Structure Data Cap-53a: (R) Cap-53b: (S)

¹H NMR (DMSO-d₆, δ = 2.5 ppm, 500 MHz): δ 12.51 (br s, 1H), 7.4 (d, J =7.9, 0.9H), 7.06 (app s, 0.1H), 3.86-3.82 (m, 1H), 3.53 (s, 3H),1.75-1.67 (m, 1H), 1.62-1.54 (m, 1H), 0.88 (d, J = 7.3, 3H). RT = 0.77minutes (Cond. 2); LC/MS: Anal. Calcd. for [M + Na]⁺ C₆H₁₁NNaO₄: 184.06;found 184.07. HRMS Calcd. for [M + Na]⁺ C₆H₁₁NNaO₄: 184.0586; found184.0592. Cap-54a: (R) Cap-54b: (S)

¹H NMR (DMSO-d₆, δ = 2.5 ppm, 500 MHz): δ 12.48 (s, 1H), 7.58 (d, J =7.6, 0.9H), 7.25 (app s, 0.1H), 3.52 (s, 3H), 3.36-3.33 (m, 1H),1.10-1.01 (m, 1H), 0.54-0.49 (m, 1H), 0.46-0.40 (m, 1H), 0.39-0.35 (m,1H), 0.31-0.21 (m, 1H). HRMS Calcd. for [M + H]⁺ C₇H₁₂NO₄: 174.0766;found 174.0771 Cap-55

¹H NMR (DMSO-d₆, δ = 2.5 ppm, 500 MHz): δ 12.62 (s, 1H), 7.42 (d, J =8.2, 0.9H), 7.07 (app s, 0.1H), 5.80-5.72 (m, 1H), 5.10 (d, J = 17.1,1H), 5.04 (d, J = 10.4, 1H), 4.01-3.96 (m, 1H), 3.53 (s, 3H), 2.47-2.42(m, 1H), 2.35-2.29 (m, 1H). Cap-56

¹H NMR (DMSO-d₆, δ = 2.5 ppm, 500 MHz): δ 12.75 (s, 1H), 7.38 (d, J =8.3, 0.9H), 6.96 (app s, 0.1H), 4.20-4.16 (m, 1H), 3.60-3.55 (m, 2H),3.54 (s, 3H), 3.24 (s, 3H). Cap-57

¹H NMR (DMSO-d₆, δ = 2.5 ppm, 500 MHz): δ 12.50 (s, 1H), 8.02 (d, J =7.7, 0.08H), 7.40 (d, J = 7.9, 0.76H), 7.19 (d, J = 8.2, 0.07H), 7.07(d, J = 6.7, 0.09H), 4.21-4.12 (m, 0.08H), 4.06-3.97 (m, 0.07H),3.96-3.80 (m, 0.85H), 3.53 (s, 3H), 1.69-1.51 (m, 2H), 1.39-1.26 (m,2H), 0.85 (t, J = 7.4, 3H). LC (Cond. 2): RT = 1.39 LC/MS: Anal. Calcd.for [M + H]⁺ C₇H₁₄NO₄: 176.09; found 176.06. Cap-58

¹H NMR (DMSO-d₆, δ = 2.5 ppm, 500 MHz): δ 12.63 (bs, 1H), 7.35 (s, 1H),7.31 (d, J = 8.2, 1H), 6.92 (s, 1H), 4.33-4.29 (m, 1H), 3.54 (s, 3H),2.54 (dd, J = 15.5, 5.4, 1H), 2.43 (dd, J = 15.6, 8.0, 1H). RT = 0.16min (Cond. 2); LC/MS: Anal. Calcd. for [M + H]⁺ C₆H₁₁N₂O₅: 191.07; found191.14. Cap-59a: (R) Cap-59b: (S)

¹H NMR (DMSO-d₆, δ = 2.5 ppm, 400 MHz): δ 12.49 (br s, 1H), 7.40 (d, J =7.3, 0.89H), 7.04 (br s, 0.11H), 4.00-3.95 (m, 3H), 1.24 (d, J = 7.3,3H), 1.15 (t, J = 7.2, 3H). HRMS: Anal. Calcd. for [M + H]⁺ C₆H₁₂NO₄:162.0766; found 162.0771. Cap-60

The crude material was purified with a reverse phase HPLC (H₂O/MeOH/TFA)to afford a colorless viscous oil that crystallized to a white solidupon exposure to high vacuum. ¹H NMR (DMSO-d₆, δ = 2.5 ppm, 400 MHz): δ12.38 (br s, 1H), 7.74 (s, 0.82H), 7.48 (s, 0.18H), 3.54/3.51 (two s,3H), 1.30 (m, 2H), 0.98 (m, 2H). HRMS: Anal. Calcd. for [M + H]⁺C₆H₁₀NO₄: 160.0610; found 160.0604. Cap-61

¹H NMR (DMSO-d₆, δ = 2.5 ppm, 400 MHz): δ 12.27 (br s, 1H), 7.40 (br s,1H), 3.50 (s, 3H), 1.32 (s, 6H). HRMS: Anal. Calcd. for [M + H]⁺C₆H₁₂NO₄: 162.0766; found 162.0765. Cap-62

¹H NMR (DMSO-d₆, δ = 2.5 ppm, 400 MHz): δ 12.74 (br s, 1H), 4.21 (d, J =10.3, 0.6H), 4.05 (d, J = 10.0, 0.4H), 3.62/3.60 (two singlets, 3H), 3.0(s, 3H), 2.14-2.05 (m, 1H), 0.95 (d, J = 6.3, 3H), 0.81 (d, J = 6.6,3H). LC/MS: Anal. Calcd. for [M − H]⁻ C₈H₁₄NO₄: 188.09; found 188.05.Cap-63

[Note: the reaction was allowed to run for longer than what was notedfor the general procedure.] ¹H NMR (DMSO-d₆, δ = 2.5 ppm, 400 MHz):12.21 (br s, 1H), 7.42 (br s, 1H), 3.50 (s, 3H), 2.02-1.85 (m, 4H),1.66-1.58 (m, 4H). LC/MS: Anal. Calcd. for [M + H]⁺ C₈H₁₄NO₄: 188.09;found 188.19. Cap-64

[Note: the reaction was allowed to run for longer than what was notedfor the general procedure.] ¹H NMR (DMSO-d₆, δ = 2.5 ppm, 400 MHz):12.35 (br s, 1H), 7.77 (s, 0.82H), 7.56/7.52 (overlapping br s, 0.18H),3.50 (s, 3H), 2.47-2.40 (m, 2H), 2.14-2.07 (m, 2H), 1.93-1.82 (m, 2H).Cap-65

Methyl chloroformate (0.65 mL, 8.39 mmol) was added dropwise over 5 minto a cooled (ice-water) mixture of Na₂CO₃ (0.449 g, 4.23 mmol), NaOH(8.2 mL of 1M/H₂O, 8.2 mmol) and (S)-2-amino-3-hydroxy-3-methylbutanoicacid (1.04 g, 7.81 mmol). The reaction mixture was stirred for 45 min,and then the cooling bath was removed and stirring was continued for anadditional 3.75 hr. The reaction mixture was washed with CH₂Cl₂, and theaqueous phase was cooled with ice-water bath and acidified withconcentrated HCl to a pH region of 1-2. The volatile component wasremoved in vacuo and the residue was taken up in a 2:1 mixture ofMeOH/CH₂Cl₂ (15 mL) and filtered, and the filterate was rotervaped toafford Cap-65 as a white semi-viscous foam (1.236 g). ¹H NMR (DMSO-d₆,δ=2.5 ppm, 400 MHz): δ 6.94 (d, J=8.5, 0.9H), 6.53 (br s, 0.1H), 3.89(d, J=8.8, 1H), 2.94 (s, 3H), 1.15 (s, 3H), 1.13 (s, 3H).

Cap-66 and -67 were prepared from appropriate commercially availablestarting materials by employing the procedure described for thesynthesis of Cap-65.

¹H NMR (DMSO-d₆, δ=2.5 ppm, 400 MHz): δ 12.58 (br s, 1H), 7.07 (d,J=8.3, 0.13H), 6.81 (d, J=8.8, 0.67H), 4.10-4.02 (m, 1.15H), 3.91 (dd,J=9.1, 3.5, 0.85H), 3.56 (s, 3H), 1.09 (d, J=6.2, 3H). [Note: only thedominant signals of NH were noted].

¹H NMR (DMSO-d₆, δ=2.5 ppm, 400 MHz): 12.51 (br s, 1H), 7.25 (d, J=8.4,0.75H), 7.12 (br d, J=0.4, 0.05H), 6.86 (br s, 0.08H), 3.95-3.85 (m,2H), 3.54 (s, 3H), 1.08 (d, J=6.3, 3H). [Note: only the dominant signalsof NH were noted]

Methyl chloroformate (0.38 ml, 4.9 mmol) was added drop-wise to amixture of 1N NaOH (aq) (9.0 ml, 9.0 mmol), 1M NaHCO₃ (aq) (9.0 ml, 9.0mol), L-aspartic acid β-benzyl ester (1.0 g, 4.5 mmol) and Dioxane (9ml). The reaction mixture was stirred at ambient conditions for 3 hr,and then washed with Ethyl acetate (50 ml, 3×). The aqueous layer wasacidified with 12N HCl to a pH˜1-2, and extracted with ethyl acetate(3×50 ml). The combined organic layers were washed with brine, dried(Na₂SO₄), filtered, and concentrated in vacuo to afford Cap-68 as alight yellow oil (1.37 g; mass is above theoretical yield, and theproduct was used without further purification). ¹H NMR (DMSO-d₆, δ=2.5ppm, 500 MHz): δ 12.88 (br s, 1H), 7.55 (d, J=8.5, 1H), 7.40-7.32 (m,5H), 5.13 (d, J=12.8, 1H), 5.10 (d, J=12.9, 1H), 4.42-4.38 (m, 1H), 3.55(s, 3H), 2.87 (dd, J=16.2, 5.5, 1H), 2.71 (dd, J=16.2, 8.3, 1H). LC(Cond. 2): RT=1.90 min; LC/MS: Anal. Calcd. For [M+H]⁺ C₁₃H₁₆NO₆:282.10. found 282.12.

NaCNBH₃ (2.416 g, 36.5 mmol) was added in batches to a chilled (˜15° C.)water (17 mL)/MeOH (10 mL) solution of alanine (1.338 g, 15.0 mmol). Afew minutes later acetaldehyde (4.0 mL, 71.3 mmol) was added drop-wiseover 4 min, the cooling bath was removed, and the reaction mixture wasstirred at ambient condition for 6 hr. An additional acetaldehyde (4.0mL) was added and the reaction was stirred for 2 hr. Concentrated HClwas added slowly to the reaction mixture until the pH reached ˜1.5, andthe resulting mixture was heated for 1 hr at 40° C. Most of the volatilecomponent was removed in vacuo and the residue was purified with aDowex® 50WX8-100 ion-exchange resin (column was washed with water, andthe compound was eluted with dilute NH₄OH, prepared by mixing 18 ml ofNH₄OH and 282 ml of water) to afford Cap-69 (2.0 g) as an off-white softhygroscopic solid. ¹H NMR (DMSO-d₆, δ=2.5 ppm, 400 MHz): δ 3.44 (q,J=7.1, 1H), 2.99-2.90 (m, 2H), 2.89-2.80 (m, 2H), 1.23 (d, J=7.1, 3H),1.13 (t, J=7.3, 6H).

Cap-70 to -74x were prepared according to the procedure described forthe synthesis of Cap-69 by employing appropriate starting materials.

Cap-70a: (R) Cap-70b: (S)

¹H NMR (DMSO-d₆, δ = 2.5 ppm, 400 MHz): δ 3.42 (q, J = 7.1, 1H),2.68-2.60 (m, 4H), 1.53-1.44 (m, 4H), 1.19 (d, J = 7.3, 3H), 0.85 (t, J= 7.5, 6H). LC/MS: Anal. Calcd. for [M + H]⁺ C₉H₂₀NO₂: 174.15; found174.13. Cap-71a: (R) Cap-71b: (S)

¹H NMR (DMSO-d₆, δ = 2.5 ppm, 500 MHz): δ 3.18-3.14 (m, 1H), 2.84-2.77(m, 2H), 2.76-2.68 (m, 2H), 1.69-1.54 (m, 2H), 1.05 (t, J = 7.2, 6H),0.91 (t, J = 7.3, 3H). LC/MS: Anal. Calcd. for [M + H]⁺ C₈H₁₈NO₂:160.13; found 160.06. Cap-72

¹H NMR (DMSO-d₆, δ = 2.5 ppm, 400 MHz): δ 2.77-2.66 (m, 3H), 2.39-2.31(m, 2H), 1.94-1.85 (m, 1H), 0.98 (t, J = 7.1, 6H), 0.91 (d, J = 6.5,3H), 0.85 (d, J = 6.5, 3H). LC/MS: Anal. Calcd. for [M + H]⁺ C₉H₂₀NO₂:174.15; found 174.15. Cap-73

¹H NMR (DMSO-d₆, δ = 2.5 ppm, 500 MHz): δ 9.5 (br s, 1H), 3.77 (dd, J =10.8, 4.1, 1H), 3.69-3.61 (m, 2H), 3.26 (s, 3H), 2.99-2.88 (m, 4H), 1.13(t, J = 7.2, 6H). Cap-74

¹H NMR (DMSO-d₆, δ = 2.5 ppm, 500 MHz): δ 7.54 (s, 1H), 6.89 (s, 1H),3.81 (t, J = 6.6, k, 1H), 2.82-2.71 (m, 4H), 2.63 (dd, J = 15.6, 7.0,1H), 2.36 (dd, J = 15.4, 6.3, 1H), 1.09 (t, J = 7.2, 6H). RT = 0.125minutes (Cond. 2); LC/MS: Anal. Calcd. for [M + H]⁺ C₈H₁₇N₂O₃: 189.12;found 189.13. Cap-74x

LC/MS: Anal. Calcd. for [M + H]⁺ C₁₀H₂₂NO₂: 188.17; found 188.21 Cap-75

Cap-75, step a

NaBH₃CN (1.6 g, 25.5 mmol) was added to a cooled (ice/water bath) water(25 ml)/methanol (15 ml) solution of H-D-Ser-OBzl HCl (2.0 g, 8.6 mmol).Acetaldehyde (1.5 ml, 12.5 mmol) was added drop-wise over 5 min, thecooling bath was removed, and the reaction mixture was stirred atambient condition for 2 hr. The reaction was carefully quenched with 12NHCl and concentrated in vacuo. The residue was dissolved in water andpurified with a reverse phase HPLC (MeOH/H₂O/TFA) to afford the TFA saltof (R)-benzyl 2-(diethylamino)-3-hydroxypropanoate as a colorlessviscous oil (1.9 g). ¹H NMR (DMSO-d₆, δ=2.5 ppm, 500 MHz): δ 9.73 (br s,1H), 7.52-7.36 (m, 5H), 5.32 (d, J=12.2, 1H), 5.27 (d, J=12.5, 1H),4.54-4.32 (m, 1H), 4.05-3.97 (m, 2H), 3.43-3.21 (m, 4H), 1.23 (t, J=7.2,6H). LC/MS (Cond. 2): RT=1.38 min; LC/MS: Anal. Calcd. for [M+H]⁺C₁₄H₂₂NO₃: 252.16. found 252.19.

Cap-75

NaH (0.0727 g, 1.82 mmol, 60%) was added to a cooled (ice-water) THF(3.0 mL) solution of the TFA salt (R)-benzyl2-(diethylamino)-3-hydroxypropanoate (0.3019 g, 0.8264 mmol) preparedabove, and the mixture was stirred for 15 min. Methyl iodide (56 μL,0.90 mmol) was added and stirring was continued for 18 hr while allowingthe bath to thaw to ambient condition. The reaction was quenched withwater and loaded onto a MeOH pre-conditioned MCX (6 g) cartridge, andwashed with methanol followed by compound elution with 2N NH₃/Methanol.Removal of the volatile component in vacuo afforded Cap-75, contaminatedwith (R)-2-(diethylamino)-3-hydroxypropanoic acid, as a yellowsemi-solid (100 mg). The product was used as is without furtherpurification.

NaCNBH₃ (1.60 g, 24.2 mmol) was added in batches to a chilled (˜15° C.)water/MeOH (12 mL each) solution of(S)-4-amino-2-(tert-butoxycarbonylamino) butanoic acid (2.17 g, 9.94mmol). A few minutes later acetaldehyde (2.7 mL, 48.1 mmol) was addeddrop-wise over 2 min, the cooling bath was removed, and the reactionmixture was stirred at ambient condition for 3.5 hr. An additionalacetaldehyde (2.7 mL, 48.1 mmol) was added and the reaction was stirredfor 20.5 hr. Most of the MeOH component was removed in vacuo, and theremaining mixture was treated with concentrated HCl until its pH reached˜1.0 and then heated for 2 hr at 40° C. The volatile component wasremoved in vacuo, and the residue was treated with 4 M HCl/dioxane (20mL) and stirred at ambient condition for 7.5 hr. The volatile componentwas removed in vacuo and the residue was purified with Dowex® 50WX8-100ion-exchange resin (column was washed with water and the compound waseluted with dilute NH₄OH, prepared from 18 ml of NH₄OH and 282 ml ofwater) to afford intermediate (S)-2-amino-4-(diethylamino)butanoic acidas an off-white solid (1.73 g).

Methyl chloroformate (0.36 mL, 4.65 mmol) was added drop-wise over 11min to a cooled (ice-water) mixture of Na₂CO₃ (0.243 g, 2.29 mmol), NaOH(4.6 mL of 1M/H₂O, 4.6 mmol) and the above product (802.4 mg). Thereaction mixture was stirred for 55 min, and then the cooling bath wasremoved and stirring was continued for an additional 5.25 hr. Thereaction mixture was diluted with equal volume of water and washed withCH₂Cl₂ (30 mL, 2×), and the aqueous phase was cooled with ice-water bathand acidified with concentrated HCl to a pH region of 2. The volatilecomponent was then removed in vacuo and the crude material wasfree-based with MCX resin (6.0 g; column was washed with water, andsample was eluted with 2.0 M NH₃/MeOH) to afford impure Cap-76 as anoff-white solid (704 mg). ¹H NMR (MeOH-d₄, δ=3.29 ppm, 400 MHz): δ 3.99(dd, J=7.5, 4.7, 1H), 3.62 (s, 3H), 3.25-3.06 (m, 6H), 2.18-2.09 (m,1H), 2.04-1.96 (m, 1H), 1.28 (t, J=7.3, 6H). LC/MS: Anal. Calcd. for[M+H]⁺ C₁₀H₂₁N₂O₄: 233.15. found 233.24.

The synthesis of Cap-77 was conducted according to the proceduredescribed for Cap-7 by using 7-azabicyclo[2.2.1]heptane for the SN₂displacement step, and by effecting the enantiomeric separation of theintermediate benzyl 2-(7-azabicyclo[2.2.1]heptan-7-yl)-2-phenylacetateusing the following condition: the intermediate (303.7 mg) was dissolvedin ethanol, and the resulting solution was injected on a chiral HPLCcolumn (Chiracel AD-H column, 30×250 mm, 5 um) eluting with 90% CO₂-10%EtOH at 70 mL/min, and a temperature of 35° C. to provide 124.5 mg ofenantiomer-1 and 133.8 mg of enantiomer-2. These benzyl esters werehydrogenolyzed according to the preparation of Cap-7 to provide Cap-77:¹H NMR (DMSO-d₆, δ=2.5 ppm, 400 MHz): δ 7.55 (m, 2H), 7.38-7.30 (m, 3H),4.16 (s, 1H), 3.54 (app br s, 2H), 2.08-1.88 (m, 4H), 1.57-1.46 (m, 4H).LC (Cond. 1): RT=0.67 min; LC/MS: Anal. Calcd. for [M+H]⁺ C₁₄H₁₈NO₂:232.13. found 232.18. HRMS: Anal. Calcd. for [M+H]⁺ Cl₄H₁₈NO₂: 232.1338.found 232.1340.

NaCNBH₃ (0.5828 g, 9.27 mmol) was added to a mixture of the HCl salt of(R)-2-(ethylamino)-2-phenylacetic acid (an intermediate in the synthesisof Cap-3; 0.9923 mg, 4.60 mmol) and(1-ethoxycyclopropoxy)trimethylsilane (1.640 g, 9.40 mmol) in MeOH (10mL), and the semi-heterogeneous mixture was heated at 50° C. with an oilbath for 20 hr. More (1-ethoxycyclopropoxy)trimethylsilane (150 mg, 0.86mmol) and NaCNBH₃ (52 mg, 0.827 mmol) were added and the reactionmixture was heated for an additional 3.5 hr. It was then allowed to coolto ambient temperature and acidified to a ˜pH region of 2 withconcentrated HCl, and the mixture was filtered and the filtrate wasrotervaped. The resulting crude material was taken up in i-PrOH (6 mL)and heated to effect dissolution, and the non-dissolved part wasfiltered off and the filtrate concentrated in vacuo. About ⅓ of theresultant crude material was purified with a reverse phase HPLC(H₂O/MeOH/TFA) to afford the TFA salt of Cap-78 as a colorless viscousoil (353 mg). ¹H NMR (DMSO-d₆, δ=2.5 ppm, 400 MHz; after D₂O exchange):δ 7.56-7.49 (m, 5H), 5.35 (S, 1H), 3.35 (m, 1H), 3.06 (app br s, 1H),2.66 (m, 1H), 1.26 (t, J=7.3, 3H), 0.92 (m, 1H), 0.83-0.44 (m, 3H). LC(Cond. 1): RT=0.64 min; LC/MS: Anal. Calcd. for [M+H]⁺ C₁₃H₁₈NO₂:220.13. found 220.21. HRMS: Anal. Calcd. for [M+H]⁺ C₁₃H₁₈NO₂: 220.1338.found 220.1343.

Ozone was bubbled through a cooled (−78° C.) CH₂Cl₂ (5.0 mL) solutionCap-55 (369 mg, 2.13 mmol) for about 50 min until the reaction mixtureattained a tint of blue color. Me₂S (10 pipet drops) was added, and thereaction mixture was stirred for 35 min. The −78° C. bath was replacedwith a −10° C. bath and stirring continued for an additional 30 min, andthen the volatile component was removed in vacuo to afford a colorlessviscous oil.

NaBH₃CN (149 mg, 2.25 mmol) was added to a MeOH (5.0 mL) solution of theabove crude material and morpholine (500 μL, 5.72 mmol) and the mixturewas stirred at ambient condition for 4 hr. It was cooled to ice-watertemperature and treated with concentrated HCl to bring its pH to ˜2.0,and then stirred for 2.5 hr. The volatile component was removed invacuo, and the residue was purified with a combination of MCX resin(MeOH wash; 2.0 N NH₃/MeOH elution) and a reverse phase HPLC(H₂O/MeOH/TFA) to afford Cap-79 containing unknown amount of morpholine.

In order to consume the morpholine contaminant, the above material wasdissolved in CH₂Cl₂ (1.5 mL) and treated with Et₃N (0.27 mL, 1.94 mmol)followed by acetic anhydride (0.10 mL, 1.06 mmol) and stirred at ambientcondition for 18 hr. THF (1.0 mL) and H₂O (0.5 mL) were added andstirring continued for 1.5 hr. The volatile component was removed invacuo, and the resultant residue was passed through MCX resin (MeOHwash; 2.0 N NH₃/MeOH elution) to afford impure Cap-79 as a brown viscousoil, which was used for the next step without further purification.

SOCl₂ (6.60 mL, 90.5 mmol) was added drop-wise over 15 min to a cooled(ice-water) mixture of (S)-3-amino-4-(benzyloxy)-4-oxobutanoic acid(10.04 g, 44.98 mmol) and MeOH (300 mL), the cooling bath was removedand the reaction mixture was stirred at ambient condition for 29 hr.Most of the volatile component was removed in vacuo and the residue wascarefully partitioned between EtOAc (150 mL) and saturated NaHCO₃solution. The aqueous phase was extracted with EtOAc (150 mL, 2×), andthe combined organic phase was dried (MgSO₄), filtered, and concentratedin vacuo to afford (S)-1-benzyl 4-methyl 2-aminosuccinate as a colorlessoil (9.706 g). ¹H NMR (DMSO-d₆, δ=2.5 ppm, 400 MHz): δ 7.40-7.32 (m,5H), 5.11 (s, 2H), 3.72 (app t, J=6.6, 1H), 3.55 (s, 3H), 2.68 (dd,J=15.9, 6.3, 1H), 2.58 (dd, J=15.9, 6.8, 1H), 1.96 (s, 2H). LC (Cond.1): RT=0.90 min; LC/MS: Anal. Calcd. for [M+H]⁺ C₁₂H₁₆NO₄: 238.11. found238.22.

Pb(NO₃)₂ (6.06 g, 18.3 mmol) was added over 1 min to a CH₂Cl₂ (80 mL)solution of (S)-1-benzyl 4-methyl 2-aminosuccinate (4.50 g, 19.0 mmol),9-bromo-9-phenyl-9H-fluorene (6.44 g, 20.0 mmol) and Et₃N (3.0 mL, 21.5mmol), and the heterogeneous mixture was stirred at ambient conditionfor 48 hr. The mixture was filtered and the filtrate was treated withMgSO₄ and filtered again, and the final filtrate was concentrated. Theresulting crude material was submitted to a Biotage purification (350 gsilica gel, CH₂Cl₂ elution) to afford (S)-1-benzyl 4-methyl2-(9-phenyl-9H-fluoren-9-ylamino)succinate as highly viscous colorlessoil (7.93 g). ¹H NMR (DMSO-d₆, δ=2.5 ppm, 400 MHz): δ 7.82 (m, 2H),7.39-7.13 (m, 16H), 4.71 (d, J=12.4, 1H), 4.51 (d, J=12.6, 1H), 3.78 (d,J=9.1, NH), 3.50 (s, 3H), 2.99 (m, 1H), 2.50-2.41 (m, 2H, partiallyoverlapped with solvent). LC (Cond. 1): RT=2.16 min; LC/MS: Anal. Calcd.for [M+H]⁺ C₃₁H₂₈NO₄: 478.20. found 478.19.

LiHMDS (9.2 mL of 1.0 M/THF, 9.2 mmol) was added drop-wise over 10 minto a cooled (−78° C.) THF (50 mL) solution of (S)-1-benzyl 4-methyl2-(9-phenyl-9H-fluoren-9-ylamino)succinate (3.907 g, 8.18 mmol) andstirred for 1 hr. MeI (0.57 mL, 9.2 mmol) was added drop-wise over 8 minto the mixture, and stirring was continued for 16.5 hr while allowingthe cooling bath to thaw to room temperature. After quenching withsaturated NH₄Cl solution (5 mL), most of the organic component wasremoved in vacuo and the residue was partitioned between CH₂Cl₂ (100 mL)and water (40 mL). The organic layer was dried (MgSO₄), filtered, andconcentrated in vacuo, and the resulting crude material was purifiedwith a Biotage (350 g silica gel; 25% EtOAc/hexanes) to afford 3.65 g ofa 2S/3S and 2S/3R diastereomeric mixtures of 1-benzyl 4-methyl3-methyl-2-(9-phenyl-9H-fluoren-9-ylamino)succinate in ˜1.0:0.65 ratio(¹H NMR). The stereochemistry of the dominant isomer was not determinedat this juncture, and the mixture was submitted to the next step withoutseparation. Partial ¹H NMR data (DMSO-d₆, δ=2.5 ppm, 400 MHz): majordiastereomer, δ 4.39 (d, J=12.3, 1H of CH₂), 3.33 (s, 3H, overlappedwith H₂O signal), 3.50 (d, J=10.9, NH), 1.13 (d, J=7.1, 3H); minordiastereomer, δ 4.27 (d, J=12.3, 1H of CH₂), 3.76 (d, J=10.9, NH), 3.64(s, 3H), 0.77 (d, J=7.0, 3H). LC (Cond. 1): RT=2.19 min; LC/MS: Anal.Calcd. for [M+H]⁺ C₃₂H₃₀NO₄: 492.22. found 492.15.

Diisobutylaluminum hydride (20.57 ml of 1.0 M in hexanes, 20.57 mmol)was added drop-wise over 10 min to a cooled (−78° C.) THF (120 mL)solution of (2S)-1-benzyl 4-methyl3-methyl-2-(9-phenyl-9H-fluoren-9-ylamino)succinate (3.37 g, 6.86 mmol)prepared above, and stirred at −78° C. for 20 hr. The reaction mixturewas removed from the cooling bath and rapidly poured into ˜1M H₃PO₄/H₂O(250 mL) with stirring, and the mixture was extracted with ether (100mL, 2×). The combined organic phase was washed with brine, dried(MgSO₄), filtered and concentrated in vacuo. A silica gel mesh of thecrude material was prepared and submitted to chromatography (25%EtOAc/hexanes; gravity elution) to afford 1.1 g of (2S,3S)-benzyl4-hydroxy-3-methyl-2-(9-phenyl-9H-fluoren-9-ylamino)butanoate,contaminated with benzyl alcohol, as a colorless viscous oil and(2S,3R)-benzyl4-hydroxy-3-methyl-2-(9-phenyl-9H-fluoren-9-ylamino)butanoate containingthe (2S,3R) stereoisomer as an impurity. The later sample wasresubmitted to the same column chromatography purification conditions toafford 750 mg of purified material as a white foam. [Note: the (2S,3S)isomer elutes before the (2S,3R) isomer under the above condition].(2S,3S) isomer: ¹H NMR (DMSO-d₆, δ=2.5 ppm, 400 MHz): 7.81 (m, 2H),7.39-7.08 (m, 16H), 4.67 (d, J=12.3, 1H), 4.43 (d, J=12.4, 1H), 4.21(app t, J=5.2, OH), 3.22 (d, J=10.1, NH), 3.17 (m, 1H), 3.08 (m, 1H),˜2.5 (m, 1H, overlapped with the solvent signal), 1.58 (m, 1H), 0.88 (d,J=6.8, 3H). LC (Cond. 1): RT=2.00 min; LC/MS: Anal. Calcd. for [M+H]⁺C₃₁H₃₀NO₃: 464.45. found 464.22. (2S,3R) isomer: ¹H NMR (DMSO-d₆, δ=2.5ppm, 400 MHz): 7.81 (d, J=7.5, 2H), 7.39-7.10 (m, 16H), 4.63 (d, J=12.1,1H), 4.50 (app t, J=4.9, 1H), 4.32 (d, J=12.1, 1H), 3.59-3.53 (m, 2H),3.23 (m, 1H), 2.44 (dd, J=9.0, 8.3, 1H), 1.70 (m, 1H), 0.57 (d, J=6.8,3H). LC (Cond. 1): RT=1.92 min; LC/MS: Anal. Calcd. for [M+H]⁺C₃₁H₃₀NO₃: 464.45. found 464.52.

The relative stereochemical assignments of the DIBAL-reduction productswere made based on NOE studies conducted on lactone derivatives preparedfrom each isomer by employing the following protocol: LiHMDS (50 μL of1.0 M/THF, 0.05 mmol) was added to a cooled (ice-water) THF (2.0 mL)solution of (2S,3S)-benzyl4-hydroxy-3-methyl-2-(9-phenyl-9H-fluoren-9-ylamino)butanoate (62.7 mg,0.135 mmol), and the reaction mixture was stirred at similar temperaturefor ˜2 hr. The volatile component was removed in vacuo and the residuewas partitioned between CH₂Cl₂ (30 mL), water (20 mL) and saturatedaqueous NH₄Cl solution (1 mL). The organic layer was dried (MgSO₄),filtered, and concentrated in vacuo, and the resulting crude materialwas submitted to a Biotage purification (40 g silica gel; 10-15%EtOAc/hexanes) to afford(3S,4S)-4-methyl-3-(9-phenyl-9H-fluoren-9-ylamino)dihydrofuran-2(3H)-oneas a colorless film of solid (28.1 mg). (2S,3R)-benzyl4-hydroxy-3-methyl-2-(9-phenyl-9H-fluoren-9-ylamino)butanoate waselaborated similarly to(3S,4R)-4-methyl-3-(9-phenyl-9H-fluoren-9-ylamino)dihydrofuran-2(3H)-one.(3S,4S)-lactone isomer: ¹H NMR (DMSO-d₆, δ=2.5 ppm, 400 MHz), 7.83 (d,J=7.5, 2H), 7.46-7.17 (m, 11H), 4.14 (app t, J=8.3, 1H), 3.60 (d, J=5.8,NH), 3.45 (app t, J=9.2, 1H), ˜2.47 (m, 1H, partially overlapped withsolvent signal), 2.16 (m, 1H), 0.27 (d, J=6.6, 3H). LC (Cond. 1):RT=1.98 min; LC/MS: Anal. Calcd. for [M+Na]⁺ C₂₄H₂₁NNaO₂: 378.15. found378.42. (3S,4R)-lactone isomer: ¹H NMR (DMSO-d₆, δ=2.5 ppm, 400 MHz),7.89 (d, J=7.6, 1H), 7.85 (d, J=7.3, 1H), 7.46-7.20 (m, 11H), 3.95 (dd,J=9.1, 4.8, 1H), 3.76 (d, J=8.8, 1H), 2.96 (d, J=3.0, NH), 2.92 (dd,J=6.8, 3, NCH), 1.55 (m, 1H), 0.97 (d, J=7.0, 3H). LC (Cond. 1): RT=2.03min; LC/MS: Anal. Calcd. for [M+Na]⁺ C₂₄H₂₁NNaO₂: 378.15. found 378.49.

TBDMS-Cl (48 mg, 0.312 mmol) followed by imidazole (28.8 mg, 0.423 mmol)were added to a CH₂Cl₂ (3 ml) solution of (2S,3S)-benzyl4-hydroxy-3-methyl-2-(9-phenyl-9H-fluoren-9-ylamino)butanoate (119.5 mg,0.258 mmol), and the mixture was stirred at ambient condition for 14.25hr. The reaction mixture was then diluted with CH₂Cl₂ (30 mL) and washedwith water (15 mL), and the organic layer was dried (MgSO₄), filtered,and concentrated in vacuo. The resultant crude material was purifiedwith a Biotage (40 g silica gel; 5% EtOAc/hexanes) to afford(2S,3S)-benzyl4-(tert-butyldimethylsilyloxy)-3-methyl-2-(9-phenyl-9H-fluoren-9-ylamino)butanoate,contaminated with TBDMS based impurities, as a colorless viscous oil(124.4 mg). (2S,3R)-benzyl4-hydroxy-3-methyl-2-(9-phenyl-9H-fluoren-9-ylamino)butanoate waselaborated similarly to (2S,3R)-benzyl4-(tert-butyldimethylsilyloxy)-3-methyl-2-(9-phenyl-9H-fluoren-9-ylamino)butanoate.(2S,3S)-silyl ether isomer: ¹H NMR (DMSO-d₆, δ=2.5 ppm, 400 MHz), 7.82(d, J=4.1, 1H), 7.80 (d, J=4.0, 1H), 7.38-7.07 (m, 16H), 4.70 (d,J=12.4, 1H), 4.42 (d, J=12.3, 1H), 3.28-3.19 (m, 3H), 2.56 (dd, J=10.1,5.5, 1H), 1.61 (m, 1H), 0.90 (d, J=6.8, 3H), 0.70 (s, 9H), −0.13 (s,3H), −0.16 (s, 3H). LC (Cond. 1, where the run time was extended to 4min): RT=3.26 min; LC/MS: Anal. Calcd. for [M+H]⁺ C₃₇H₄₄NO₃Si: 578.31.found 578.40. (2S,3R)-silyl ether isomer: ¹H NMR (DMSO-d₆, δ=2.5 ppm,400 MHz), 7.82 (d, J=3.0, 1H), 7.80 (d, J=3.1, 1H), 7.39-7.10 (m, 16H),4.66 (d, J=12.4, 1H), 4.39 (d, J=12.4, 1H), 3.61 (dd, J=9.9, 5.6, 1H),3.45 (d, J=9.5, 1H), 3.41 (dd, J=10, 6.2, 1H), 2.55 (dd, J=9.5, 7.3,1H), 1.74 (m, 1H), 0.77 (s, 9H), 0.61 (d, J=7.1, 3H), −0.06 (s, 3H),−0.08 (s, 3H).

A balloon of hydrogen was attached to a mixture of (2S,3S)-benzyl4-(tert-butyldimethylsilyloxy)-3-methyl-2-(9-phenyl-9H-fluoren-9-ylamino)butanoate(836 mg, 1.447 mmol) and 10% Pd/C (213 mg) in EtOAc (16 mL) and themixture was stirred at room temperature for ˜21 hr, where the balloonwas recharged with H₂ as necessary. The reaction mixture was dilutedwith CH₂Cl₂ and filtered through a pad of diatomaceous earth(Celite-545®), and the pad was washed with EtOAc (200 mL), EtOAc/MeOH(1:1 mixture, 200 mL) and MeOH (750 mL). The combined organic phase wasconcentrated, and a silica gel mesh was prepared from the resultingcrude material and submitted to a flash chromatography (8:2:1 mixture ofEtOAc/i-PrOH/H₂O) to afford(2S,3S)-2-amino-4-(tert-butyldimethylsilyloxy)-3-methylbutanoic acid asa white fluffy solid (325 mg). (2S,3R)-benzyl4-(tert-butyldimethylsilyloxy)-3-methyl-2-(9-phenyl-9H-fluoren-9-ylamino)butanoatewas similarly elaborated to(2S,3R)-2-amino-4-(tert-butyldimethylsilyloxy)-3-methylbutanoic acid.(2S,3S)-amino acid isomer: ¹H NMR (Methanol-d₄, δ=3.29 ppm, 400 MHz),3.76 (dd, J=10.5, 5.2, 1H), 3.73 (d, J=3.0, 1H), 3.67 (dd, J=10.5, 7.0,H), 2.37 (m, 1H), 0.97 (d, J=7.0, 3H), 0.92 (s, 9H), 0.10 (s, 6H).LC/MS: Anal. Calcd. for [M+H]⁺ C₁₁H₂₆NO₃Si: 248.17. found 248.44.(2S,3R)-amino acid isomer: ¹H NMR (Methanol-d₄, δ=3.29 ppm, 400 MHz),3.76-3.75 (m, 2H), 3.60 (d, J=4.1, 1H), 2.16 (m, 1H), 1.06 (d, J=7.3,3H), 0.91 (s, 9H), 0.09 (s, 6H). Anal. Calcd. for [M+H]⁺ C₁₁H₂₆NO₃Si:248.17. found 248.44.

Water (1 mL) and NaOH (0.18 mL of 1.0 M/H₂O, 0.18 mmol) were added to amixture of(2S,3S)-2-amino-4-(tert-butyldimethylsilyloxy)-3-methylbutanoic acid(41.9 mg, 0.169 mmol) and Na₂CO₃ (11.9 mg, 0.112 mmol), and sonicatedfor about 1 min to effect dissolution of reactants. The mixture was thencooled with an ice-water bath, methyl chloroformate (0.02 mL, 0.259mmol) was added over 30 s, and vigorous stirring was continued atsimilar temperature for 40 min and then at ambient temperature for 2.7hr. The reaction mixture was diluted with water (5 mL), cooled withice-water bath and treated drop-wise with 1.0 N HCl aqueous solution(˜0.23 mL). The mixture was further diluted with water (10 mL) andextracted with CH₂Cl₂ (15 mL, 2×). The combined organic phase was dried(MgSO₄), filtered, and concentrated in vacuo to afford Cap-80a as anoff-white solid.(2S,3R)-2-amino-4-(tert-butyldimethylsilyloxy)-3-methylbutanoic acid wassimilarly elaborated to Cap-80b. Cap-80a: ¹H NMR (DMSO-d₆, δ=2.5 ppm,400 MHz), 12.57 (br s, 1H), 7.64 (d, J=8.3, 0.3H), 7.19 (d, J=8.8,0.7H), 4.44 (dd, J=8.1, 4.6, 0.3H), 4.23 (dd, J=8.7, 4.4, 0.7H),3.56/3.53 (two singlets, 3H), 3.48-3.40 (m, 2H), 2.22-2.10 (m, 1H), 0.85(s, 9H), ˜0.84 (d, 0.9H, overlapped with t-Bu signal), 0.79 (d, J=7,2.1H), 0.02/0.01/0.00 (three overlapping singlets, 6H). LC/MS: Anal.Calcd. for [M+Na]⁺ C₁₃H₂₇NNaO₅Si: 328.16. found 328.46. Cap-80b: ¹H NMR(CDCl₃, δ=7.24 ppm, 400 MHz), 6.00 (br d, J=6.8, 1H), 4.36 (dd, J=7.1,3.1, 1H), 3.87 (dd, J=10.5, 3.0, 1H), 3.67 (s, 3H), 3.58 (dd, J=10.6,4.8, 1H), 2.35 (m, 1H), 1.03 (d, J=7.1, 3H), 0.90 (s, 9H), 0.08 (s, 6H).LC/MS: Anal. Calcd. for [M+Na]⁺ C₁₃H₂₇NNaO₅Si: 328.16. found 328.53. Thecrude products were utilized without further purification.

Prepared according to the protocol described by Falb et al. SyntheticCommunications 1993, 23, 2839.

Cap-82 to Cap-85

Cap-82 to Cap-85 were synthesized from appropriate starting materialsaccording to the procedure described for Cap-51 or Cap-13. The samplesexhibited similar spectral profiles as that of their enantiomers (i.e.,Cap-4, Cap-13, Cap-51 and Cap-52, respectively)

To a mixture of O-methyl-L-threonine (3.0 g, 22.55 mmol), NaOH (0.902 g,22.55 mmol) in H₂O (15 mL) was added ClCO₂Me (1.74 mL, 22.55 mmol)dropwise at 0° C. The mixture was allowed to stir for 12 h and acidifiedto pH 1 using 1N HCl. The aqueous phase was extracted with EtOAc and(2×250 mL) and 10% MeOH in CH₂Cl₂ (250 mL) and the combined organicphases were concentrated under in vacuo to afford a colorless oil (4.18g, 97%) which was of sufficient purity for use in subsequent steps.¹HNMR (400 MHz, CDCl₃) δ 4.19 (s, 1H), 3.92-3.97 (m, 1H), 3.66 (s, 3H),1.17 (d, J=7.7 Hz, 3H). LCMS: Anal. Calcd. for C₇H₁₃NO₅: 191. found: 190(M−H)⁻.

To a mixture of L-homoserine (2.0 g, 9.79 mmol), Na₂CO₃ (2.08 g, 19.59mmol) in H₂O (15 mL) was added ClCO₂Me (0.76 mL, 9.79 mmol) dropwise at0° C. The mixture was allowed to stir for 48 h and acidified to pH 1using 1N HCl. The aqueous phase was extracted with EtOAc and (2×250 mL)and the combined organic phases were concentrated under in vacuo toafford a colorless solid (0.719 g, 28%) which was of sufficient purityfor use in subsequent steps. ¹HNMR (400 MHz, CDCl₃) δ 4.23 (dd, J=4.5,9.1 Hz, 1H), 3.66 (s, 3H), 3.43-3.49 (m, 2H), 2.08-2.14 (m, 1H),1.82-1.89 (m, 1H). LCMS: Anal. Calcd. for C₇H₁₃NO₅: 191. found: 192(M+H)⁺.

A mixture of L-valine (1.0 g, 8.54 mmol), 3-bromopyridine (1.8 mL, 18.7mmol), K₂CO₃ (2.45 g, 17.7 mmol) and CuI (169 mg, 0.887 mmol) in DMSO(10 mL) was heated at 100° C. for 12 h. The reaction mixture was cooledto rt, poured into H₂O (ca. 150 mL) and washed with EtOAc (×2). Theorganic layers were extracted with a small amount of H₂O and thecombined aq phases were acidified to ca. pH 2 with 6N HCl. The volumewas reduced to about one-third and 20 g of cation exchange resin(Strata) was added. The slurry was allowed to stand for 20 min andloaded onto a pad of cation exchange resin (Strata) (ca. 25 g). The padwas washed with H₂O (200 mL), MeOH (200 mL), and then NH₃ (3M in MeOH,2×200 mL). The appropriate fractions was concentrated in vacuo and theresidue (ca. 1.1 g) was dissolved in H₂O, frozen and lyophyllized. Thetitle compound was obtained as a foam (1.02 g, 62%). ¹HNMR (400 MHz,DMSO-d₆) δ 8.00 (s, br, 1H), 7.68-7.71 (m, 1H), 7.01 (s, br, 1H), 6.88(d, J=7.5 Hz, 1H), 5.75 (s, br, 1H), 3.54 (s, 1H), 2.04-2.06 (m, 1H),0.95 (d, J=6.0 Hz, 3H), 0.91 (d, J=6.6 Hz, 3H). LCMS: Anal. Calcd. forC₁₀H₁₄N₂O₂: 194. found: 195 (M+H)⁺.

A mixture of L-valine (1.0 g, 8.54 mmol), 5-bromopyrimidine (4.03 g,17.0 mmol), K₂CO₃ (2.40 g, 17.4 mmol) and CuI (179 mg, 0.94 mmol) inDMSO (10 mL) was heated at 100° C. for 12 h. The reaction mixture wascooled to RT, poured into H₂O (ca. 150 mL) and washed with EtOAc (×2).The organic layers were extracted with a small amount of H₂O and thecombined aq phases were acidified to ca. pH 2 with 6N HCl. The volumewas reduced to about one-third and 20 g of cation exchange resin(Strata) was added. The slurry was allowed to stand for 20 min andloaded onto a pad of cation exchange resin (Strata) (ca. 25 g). The padwas washed with H₂O (200 mL), MeOH (200 mL), and then NH₃ (3M in MeOH,2×200 mL). The appropriate fractions was concentrated in vacuo and theresidue (ca. 1.1 g) was dissolved in H₂O, frozen and lyophyllized. Thetitle compound was obtained as a foam (1.02 g, 62%). ¹HNMR (400 MHz,CD₃OD) showed the mixture to contain valine and the purity could not beestimated. The material was used as is in subsequent reactions. LCMS:Anal. Calcd. for C₉H₁₃N₃O₂: 195. found: 196 (M+H)⁺.

Cap-90 was prepared according to the method described for thepreparation of Cap-1. The crude material was used as is in subsequentsteps. LCMS: Anal. Calcd. for C₁₁H₁₅NO₂: 193. found: 192 (M−H)⁻.The following caps were prepared according to the method used forpreparation of cap 51 unless noted otherwise:

Cap Structure LCMS Cap-91

LCMS: Anal. Calcd. for C₁₁H₁₃NO₄: 223; found: 222 (M − H)⁻. Cap-92

LCMS: Anal. Calcd. for C₁₁H₁₃NO₄: 223; found: 222 (M − H)⁻. Cap-93

LCMS: Anal. Calcd. for C₁₀H₁₂N₂O₄: 224; found: 225 (M + H)⁺. Cap-94

LCMS: Anal. Calcd. for C₈H₁₁N₃O₄: 213; found: 214 (M + H)⁺. Cap-95

LCMS: Anal. Calcd. for C₁₃H₁₇NO₄: 251; found: 250 (M − H)⁻. Cap-96

LCMS: Anal. Calcd. for C₁₂H₁₅ NO₄: 237; found: 236 (M − H)⁻. Cap-97

LCMS: Anal. Calcd. for C₉H₁₅ NO₄: 201; found: 200 (M − H)⁻. Cap-98

LCMS: Anal. Calcd. for C₉H₁₅ NO₄: 201; found: 202 (M + H)⁺. Cap-99

¹H NMR (400 MHz, CD₃OD) δ 3.88-3.94 (m, 1H), 3.60, 3.61 (s, 3H), 2.80(m, 1H), 2.20 (m, 1H), 1.82-1.94 (m, 3H), 1.45-1.71 (m, 2H). Cap-99a

¹H NMR (400 MHz, CD₃OD) δ 3.88-3.94 (m, 1H), 3.60, 3.61 (s, 3H), 2.80(m, 1H), 2.20 (m 1H), 1.82-1.94 (m, 3H), 1.45-1.71 (m, 2H). Cap-100

LCMS: Anal. Calcd. for C₁₂H₁₄NO₄F: 255; found: 256 (M + H)⁺. Cap-101

LCMS: Anal. Calcd. for C₁₁H₁₃NO₄: 223; found: 222 (M − H)⁻. Cap-102

LCMS: Anal. Calcd. for C₁₁H₁₃NO₄: 223; found: 222 (M − H)⁻ Cap-103

LCMS: Anal. Calcd. for C₁₀H₁₂N₂O₄: 224; found: 225 (M + H)⁺. Cap-104

¹HNMR (400 MHz, CD₃OD) δ 3.60 (s, 3H), 3.50-3.53 (m, 1H), 2.66-2.69 and2.44-2.49 (m, 1H), 1.91-2.01 (m, 2H), 1.62-1.74 (m, 4H), 1.51-1.62 (m,2H). Cap-105

¹HNMR (400 MHz, CD₃OD) δ 3.60 (s, 3H), 3.33-3.35 (m, 1H, partiallyobscured by solvent), 2.37-2.41 and 2.16-2.23 (m, 1H), 1.94-2.01 (m,4H), 1.43-1.53 (m, 2H), 1.17-1.29 (m, 2H). Cap-106

¹HNMR (400 MHz, CD₃OD) δ 3.16 (q, J = 7.3 Hz, 4H), 2.38-2.41 (m, 1H),2.28-2.31 (m, 2H), 1.79-1.89 (m, 2H), 1.74 (app, ddd J = 3.5, 12.5, 15.9Hz, 2H), 1.46 (app dt J = 4.0, 12.9 Hz, 2H), 1.26 (t, J = 7.3 Hz, 6H)Cap-107

LCMS: Anal. Calcd. for C₈H₁₀N₂O₄S: 230; found: 231 (M + H)⁺. Cap-108

LCMS: Anal. Calcd. for C₁₅H₁₇N₃O₄: 303; found: 304 (M + H)⁺. Cap-109

LCMS: Anal. Calcd. for C₁₀H₁₂N₂O₄: 224; found: 225 (M + H)⁺. Cap-110

LCMS: Anal. Calcd. for C₁₀H₁₂N₂O₄: 224; found: 225 (M + H)⁺. Cap-111

LCMS: Anal. Calcd. for C₁₂H₁₆NO₈P: 333; found: 334 (M + H)⁺. Cap-112

LCMS: Anal. Calcd. for C₁₃H₁₄N₂O₄: 262; found: 263 (M + H)⁺. Cap-113

LCMS: Anal. Calcd. for C₁₈H₁₉NO₅: 329; found: 330 (M + H)⁺. Cap-114

¹HNMR (400 MHz, CDCl₃) δ 4.82-4.84 (m, 1H), 4.00-4.05 (m, 2H), 3.77 (s,3H), 2.56 (s, br, 2H) Cap-115

¹HNMR (400 MHz, CDCl₃) δ 5.13 (s, br, 1H), 4.13 (s, br, 1H), 3.69 (s,3H), 2.61 (d, J = 5.0 Hz, 2H), 1.28 (d, J = 9.1 Hz, 3H). Cap-116

¹HNMR (400 MHz, CDCl₃) δ 5.10 (d, J = 8.6 Hz, 1H), 3.74-3.83 (m, 1H),3.69 (s, 3H), 2.54-2.61 (m, 2H), 1.88 (sept, J = 7.0 Hz, 1H), 0.95 (d, J= 7.0 Hz, 6H).

Cap-117 to Cap-123

For the preparation of caps Cap-117 to Cap-123 the Boc amino acids werecommercially available and were deprotected by treatment with 25% TFA inCH₂Cl₂. After complete reaction as judged by LCMS the solvents wereremoved in vacuo and the corresponding TFA salt of the amino acid wascarbamoylated with methyl chloroformate according to the procedure forCap-51.

Cap Structure LCMS Cap-117

LCMS: Anal. Calcd. for C₁₂H₁₅ NO₄: 237; found: 238 (M + H)⁺. Cap-118

LCMS: Anal. Calcd. for C₁₀H₁₃NO₄S: 243; found: 244 (M + H)⁺. Cap-119

LCMS: Anal. Calcd. for C₁₀H₁₃NO₄S: 243; found: 244 (M + H)⁺. Cap-120

LCMS: Anal. Calcd. for C₁₀H₁₃NO₄S: 243; found: 244 (M + H)⁺. Cap-121

¹HNMR (400 MHz, CDCl₃) δ 4.06-4.16 (m, 1H), 3.63 (s, 3H), 3.43 (s, 1H),2.82 and 2.66 (s, br, 1H), 1.86-2.10 (m, 3H), 1.64-1.76 (m, 2H),1.44-1.53 (m, 1H). Cap-122

¹HNMR profile is similar to that of its enantiomer, Cap-121. Cap-123

LCMS: Anal. Calcd. for C₂₇H₂₆N₂O₆: 474; found: 475 (M + H)⁺.

Preparation of Cap-124. (4S,5R)-5-methyl-2-oxooxazolidine-4-carboxylicacid

The hydrochloride salt of L-threonine tert-butyl ester was carbamoylatedaccording to the procedure for Cap-51. The crude reaction mixture wasacidified with 1N HCl to pH˜1 and the mixture was extracted with EtOAc(2×50 mL). The combined organic phases were concentrated in vacuo togive a colorless oil which solidified on standing. The aqueous layer wasconcentrated in vacuo and the resulting mixture of product and inorganicsalts was triturated with EtOAc-CH₂Cl₂-MeOH (1:1:0.1) and then theorganic phase concentrated in vacuo to give a colorless oil which wasshown by LCMS to be the desired product. Both crops were combined togive 0.52 g of a solid. ¹HNMR (400 MHz, CD₃OD) δ 4.60 (m, 1H), 4.04 (d,J=5.0 Hz, 1H), 1.49 (d, J=6.3 Hz, 3H). LCMS: Anal. Calcd. for C₅H₇NO₄:145. found: 146 (M+H)⁺.

Preparation of Cap-125.(S)-2-(tert-butoxycarbonylamino)-4-(dimethylamino)butanoic acid

To a suspension of Pd(OH)₂, (20%, 100 mg), aqueous formaldehyde (37% wt,4 ml), acetic acid, (0.5 mL) in methanol (15 mL) was added(S)-4-amino-2-(tert-butoxycarbonylamino)butanoic acid (1 g, 4.48 mmol).The reaction was purged several times with hydrogen and was stirredovernight with an hydrogen balloon room temp. The reaction mixture wasfiltered through a pad of diatomaceous earth (Celite™), and the volatilecomponent was removed in vacuo. The resulting crude material was used asis for the next step. LC/MS: Anal. Calcd. for C₁₁H₂₂N₂O₄: 246. found:247 (M+H)⁺.

Preparation of 3-methyl-N-[(methyloxy)carbonyl]-L-histidine (Cap-126)

This procedure is a modification of that used to prepare Cap-51. To asuspension of 3-methyl-L-histidine (0.80 g, 4.70 mmol) in THF (10 mL)and H₂O (10 mL) at 0° C. was added NaHCO₃ (0.88 g, 10.5 mmol). Theresulting mixture was treated with ClCO₂Me (0.40 mL, 5.20 mmol) and themixture allowed to stir at 0° C. After stirring for ca. 2 h LCMS showedno starting material remaining. The reaction was acidified to pH 2 with6 N HCl.

The solvents were removed in vacuo and the residue was suspended in 20mL of 20% MeOH in CH₂Cl₂. The mixture was filtered and concentrated togive a light yellow foam (1.21 g). LCMS and ¹H NMR showed the materialto be a 9:1 mixture of the methyl ester and the desired product. Thismaterial was taken up in THF (10 mL) and H₂O (10 mL), cooled to 0° C.and LiOH (249.1 mg, 10.4 mmol) was added. After stirring ca. 1 h LCMSshowed no ester remaining. Therefore the mixture was acidified with 6NHCl and the solvents removed in vacuo. LCMS and ¹H NMR confirm theabsence of the ester. The title compound was obtained as its HCl saltcontaminated with inorganic salts (1.91 g, >100%). The compound was usedas is in subsequent steps without further purification. ¹HNMR (400 MHz,CD₃OD) δ 8.84, (s, 1H), 7.35 (s, 1H), 4.52 (dd, J=5.0, 9.1 Hz, 1H), 3.89(s, 3H), 3.62 (s, 3H), 3.35 (dd, J=4.5, 15.6 Hz, 1H, partially obscuredby solvent), 3.12 (dd, J=9.0, 15.6 Hz, 1H). LCMS: Anal. Calcd. forC₉H₁₃N₃O₄: 227.09. found: 228.09 (M+H)⁺.

Preparation of(S)-2-(methoxycarbonylamino)-3-(1-methyl-1H-imidazol-4-yl)propanoic acid(Cap-127)

Cap-127 was prepared according to the method for Cap-126 above startingfrom (S)-2-amino-3-(1-methyl-1H-imidazol-4-yl)propanoic acid (1. II g,6.56 mmol), NaHCO₃ (1.21 g, 14.4 mmol) and ClCO₂Me (0.56 mL, 7.28 mmol).The title compound was obtained as its HCl salt (1.79 g, >100%)contaminated with inorganic salts. LCMS and ¹H NMR showed the presenceof ca. 5% of the methyl ester. The crude mixture was used as is withoutfurther purification. ¹HNMR (400 MHz, CD₃OD) δ 8.90 (s, 1H), 7.35 (s,1H), 4.48 (dd, J=5.0, 8.6 Hz, 1H), 3.89 (s, 3H), 3.62 (s, 3H), 3.35 (m,1H), 3.08 (m, 1H); LCMS: Anal. Calcd. for C₉H₁₃N₃O₄: 227.09. found: 228(M+H)⁺.

Preparation of(S)-2-(methoxycarbonylamino)-3-(1H-1,2,3-triazol-4-yl)propanoic acid(Cap-128)

Step 1. Preparation of (S)-benzyl2-(tert-butoxycarbonylamino)pent-4-ynoate (cj-27b)

To a solution of cj-27a (1.01 g, 4.74 mmol), DMAP (58 mg, 0.475 mmol)and iPr₂NEt (1.7 mL, 9.8 mmol) in CH₂Cl₂ (100 mL) at 0° C. was addedCbz-Cl (0.68 mL, 4.83 mmol). The solution was allowed to stir for 4 h at0° C., washed (1N KHSO₄, brine), dried (Na₂SO₄), filtered, andconcentrated in vacuo. The residue was purified by flash columnchromatography (TLC 6:1 hex:EtOAc) to give the title compound (1.30 g,91%) as a colorless oil. ¹HNMR (400 MHz, CDCl₃) δ 7.35 (s, 5H), 5.35 (d,br, J=8.1 Hz, 1H), 5.23 (d, J=12.2 Hz, 1H), 5.17 (d, J=12.2 Hz, 1H),4.48-4.53 (m, 1H), 2.68-2.81 (m, 2H), 2.00 (t, J=2.5 Hz, 1H), 1.44 (s,9H). LCMS: Anal. Calcd. for C₁₇H₂₁NO₄: 303. found: 304 (M+H)⁺.

Step 2. Preparation of (S)-benzyl3-(1-benzyl-1H-1,2,3-triazol-4-yl)-2-(tert-butoxycarbonylamino)propanoate(cj-28)

To a mixture of (S)-benzyl 2-(tert-butoxycarbonylamino)pent-4-ynoate(0.50 g, 1.65 mmol), sodium ascorbate (0.036 g, 0.18 mmol), CuSO₄-5H₂O(0.022 g, 0.09 mmol) and NaN₃ (0.13 g, 2.1 mmol) in DMF-H₂O (5 mL, 4:1)at rt was added BnBr (0.24 mL, 2.02 mmol) and the mixture was warmed to65° C. After 5 h LCMS indicated low conversion. A further portion ofNaN₃ (100 mg) was added and heating was continued for 12 h. The reactionwas poured into EtOAc and H₂O and shaken. The layers were separated andthe aqueous layer extracted 3× with EtOAc and the combined organicphases washed (H₂O×3, brine), dried (Na₂SO₄), filtered, andconcentrated. The residue was purified by flash (Biotage, 40+M 0-5% MeOHin CH₂Cl₂; TLC 3% MeOH in CH₂Cl₂) to afford a light yellow oil whichsolidified on standing (748.3 mg, 104%). The NMR was consistent with thedesired product but suggests the presence of DMF. The material was usedas is without further purification. ¹HNMR (400 MHz, DMSO-d₆) δ 7.84 (s,1H), 7.27-7.32 (m, 10H), 5.54 (s, 2H), 5.07 (s, 2H), 4.25 (m, 1H), 3.16(dd, J=1.0, 5.3 Hz, 1H), 3.06 (dd, J=5.3, 14.7 Hz), 2.96 (dd, J=9.1,14.7 Hz, 1H), 1.31 (s, 9H). LCMS: Anal. Calcd. for C₂₄H₂₈N₄O₄: 436.found: 437 (M+H)⁺.

Step 2. Preparation of (S)-benzyl3-(1-benzyl-1H-1,2,3-triazol-4-yl)-2-(methoxycarbonylamino)propanoate(cj-29)

A solution of (S)-benzyl3-(1-benzyl-1H-1,2,3-triazol-4-yl)-2-(tert-butoxycarbonylamino)propanoate(0.52 g, 1.15 mmol) in CH₂Cl₂ was added TFA (4 mL). The mixture wasallowed to stir at room temperature for 2 h. The mixture wasconcentrated in vacuo to give a colorless oil which solidified onstanding. This material was dissolved in THF-H₂O and cooled to 0° C.Solid NaHCO₃ (0.25 g, 3.00 mmol) was added followed by ClCO₂Me (0.25 mL,3.25 mmol). After stirring for 1.5 h the mixture was acidified to pH˜2with 6N HCl and then poured into H₂O-EtOAc. The layers were separatedand the aq phase extracted 2× with EtOAc. The combined org layers werewashed (H₂O, brine), dried (Na₂SO₄), filtered, and concentrated in vacuoto give a colorless oil (505.8 mg, 111%, NMR suggested the presence ofan unidentified impurity) which solidified while standing on the pump.The material was used as is without further purification. ¹HNMR (400MHz, DMSO-d₆) δ 7.87 (s, 1H), 7.70 (d, J=8.1 Hz, 1H), 7.27-7.32 (m,10H), 5.54 (s, 2H), 5.10 (d, J=12.7 Hz, 1H), 5.06 (d, J=12.7 Hz, 1H),4.32-4.37 (m, 1H), 3.49 (s, 3H), 3.09 (dd, J=5.6, 14.7 Hz, 1H), 2.98(dd, J=9.6, 14.7 Hz, 1H). LCMS: Anal. Calcd. for C₂₁H₂₂N₄O₄: 394. found:395 (M+H)⁺.

Step 3. Preparation of(S)-2-(methoxycarbonylamino)-3-(1H-1,2,3-triazol-4-yl)propanoic acid(Cap-128)

(S)-benzyl3-(1-benzyl-1H-1,2,3-triazol-4-yl)-2-(methoxycarbonylamino)propanoate(502 mg, 1. II mmol) was hydrogenated in the presence of Pd—C (82 mg) inMeOH (5 mL) at atmospheric pressure for 12 h. The mixture was filteredthrough diatomaceous earth (Celite™) and concentrated in vacuo.(S)-2-(methoxycarbonylamino)-3-(1H-1,2,3-triazol-4-yl)propanoic acid wasobtained as a colorless gum (266 mg, 111%) which was contaminated withca. 10% of the methyl ester. The material was used as is without furtherpurification.

¹HNMR (400 MHz, DMSO-d₆) δ 12.78 (s, br, 1H), 7.59 (s, 1H), 7.50 (d,J=8.0 Hz, 1H), 4.19-4.24 (m, 1H), 3.49 (s, 3H), 3.12 (dd, J=4.8 Hz, 14.9Hz, 1H), 2.96 (dd, J=9.9, 15.0 Hz, 1H). LCMS: Anal. Calcd. forC₇H₁₀N₄O₄: 214. found: 215 (M+H)⁺.

Preparation of (S)-2-(methoxycarbonylamino)-3-(1H-pyrazol-1-yl)propanoicacid (Cap-129)

Step 1. Preparation of(S)-2-(benzyloxycarbonylamino)-3-(1H-pyrazol-1-yl)propanoic acid (cj-31)

A suspension of (S)-benzyl 2-oxooxetan-3-ylcarbamate (0.67 g, 3.03mmol), and pyrazole (0.22 g, 3.29 mmol) in CH₃CN (12 mL) was heated at50° C. for 24 h. The mixture was cooled to rt overnight and the solidfiltered to afford(S)-2-(benzyloxycarbonylamino)-3-(1H-pyrazol-1-yl)propanoic acid (330.1mg). The filtrate was concentrated in vacuo and then triturated with asmall amount of CH₃CN (ca. 4 mL) to afford a second crop (43.5 mg).Total yield 370.4 mg (44%). m.p. 165.5-168° C. lit m.p. 168.5-169.5[Vederas et al. J. Am. Chem. Soc. 1985, 107, 7105]. ¹HNMR (400 MHz,CD₃OD) δ 7.51 (d, J=2.0, 1H), 7.48 (s, J=1.5 Hz, 1H), 7.24-7.34 (m, 5H),6.23 m, 1H), 5.05 (d, 12.7H, 1H), 5.03 (d, J=12.7 Hz, 1H), 4.59-4.66 (m,2H), 4.42-4.49 (m, 1H). LCMS: Anal. Calcd. for C₁₄H₁₅N₃O₄: 289. found:290 (M+H)⁺.

Step 2. Preparation of(S)-2-(methoxycarbonylamino)-3-(1H-pyrazol-1-yl)propanoic acid (Cap-129)

(S)-2-(benzyloxycarbonylamino)-3-(1H-pyrazol-1-yl)propanoic acid (0.20g, 0.70 mmol) was hydrogenated in the presence of Pd—C (45 mg) in MeOH(5 mL) at atmospheric pressure for 2 h. The product appeared to beinsoluble in MeOH, therefore the reaction mixture was diluted with 5 mLH₂O and a few drops of 6N HCl. The homogeneous solution was filteredthrough diatomaceous earth (Celite™), and the MeOH removed in vacuo. Theremaining solution was frozen and lyophyllized to give a yellow foam(188.9 mg). This material was suspended in THF-H₂O (1:1, 10 mL) and thencooled to 0° C. To the cold mixture was added NaHCO₃ (146.0 mg, 1.74mmol) carefully (evolution of CO₂). After gas evolution had ceased (ca.15 min) ClCO₂Me (0.06 mL, 0.78 mmol) was added dropwise. The mixture wasallowed to stir for 2 h and was acidified to pH˜2 with 6N HCl and pouredinto EtOAc. The layers were separated and the aqueous phase extractedwith EtOAC (×5). The combined organic layers were washed (brine), dried(Na₂SO₄), filtered, and concentrated to give the title compound as acolorless solid (117.8 mg, 79%). ¹HNMR (400 MHz, DMSO-d₆) δ 13.04 (s,1H), 7.63 (d, J=2.6 Hz, 1H), 7.48 (d, J=8.1 Hz, 1H), 7.44 (d, J=1.5 Hz,1H), 6.19 (app t, J=2.0 Hz, 1H), 4.47 (dd, J=3.0, 12.9 Hz, 1H),4.29-4.41 (m, 2H), 3.48 (s, 3H). LCMS: Anal. Calcd. for C₈H₁₁N₃O₄: 213.found: 214 (M+H)⁺.

Cap-130 was prepared by acylation of commercially available(R)-phenylglycine analgous to the procedure given in: Calmes, M.;Daunis, J.; Jacquier, R.; Verducci, J. Tetrahedron, 1987, 43(10), 2285.

Step a: Dimethylcarbamoyl chloride (0.92 mL, 10 mmol) was added slowlyto a solution of (S)-benzyl 2-amino-3-methylbutanoate hydrochloride(2.44 g; 10 mmol) and Hunig's base (3.67 mL, 21 mmol) in THF (50 mL).The resulting white suspension was stirred at room temperature overnight(16 hours) and concentrated under reduced pressure. The residue waspartitioned between ethyl acetate and water. The organic layer waswashed with brine, dried (MgSO₄), filtered, and concentrated underreduced pressure. The resulting yellow oil was purified by flashchromatography, eluting with ethyl acetate:hexanes (1:1). Collectedfractions were concentrated under vacuum providing 2.35 g (85%) of clearoil. ¹H NMR (300 MHz, DMSO-d₆) δ ppm 0.84 (d, J=6.95 Hz, 3H) 0.89 (d,J=6.59 Hz, 3H) 1.98-2.15 (m, 1H) 2.80 (s, 6H) 5.01-5.09 (m, J=12.44 Hz,1H) 5.13 (d, J=12.44 Hz, 1H) 6.22 (d, J=8.05 Hz, 1H) 7.26-7.42 (m, 5H).LC (Cond. 1): RT=1.76 min; MS: Anal. Calcd. for [M+H]⁺ C₁₆H₂₂N₂O₃:279.17. found 279.03.Step b: To a MeOH (50 mL) solution of the intermediate prepared above(2.35 g; 8.45 mmol) was added Pd/C (10%; 200 mg) and the resulting blacksuspension was flushed with N₂ (3×) and placed under 1 atm of H₂. Themixture was stirred at room temperature overnight and filtered though amicrofiber filter to remove the catalyst. The resulting clear solutionwas then concentrated under reduced pressure to obtain 1.43 g (89%) ofCap-131 as a white foam, which was used without further purification. ¹HNMR (500 MHz, DMSO-d₆) δ ppm 0.87 (d, J=4.27 Hz, 3H) 0.88 (d, J=3.97 Hz,3H) 1.93-2.11 (m, 1H) 2.80 (s, 6H) 3.90 (dd, J=8.39, 6.87 Hz, 1H) 5.93(d, J=8.54 Hz, 1H) 12.36 (s, 1H).). LC (Cond. 1): RT=0.33 min; MS: Anal.Calcd. for [M+H]⁺ C₈H₁₇N₂O₃: 1898.12. found 189.04.

Cap-132 was prepared from (S)-benzyl 2-aminopropanoate hydrochlorideaccording to the method described for Cap-131. ¹H NMR (500 MHz, DMSO-d₆)δ ppm 1.27 (d, J=7.32 Hz, 3H) 2.80 (s, 6H) 4.06 (qt, 1H) 6.36 (d, J=7.32Hz, 1H) 12.27 (s, 1H). LC (Cond. 1): RT=0.15 min; MS: Anal. Calcd. for[M+H]⁺ C₆H₁₃N₂O₃: 161.09. found 161.00.

Cap-133 was prepared from (S)-tert-butyl 2-amino-3-methylbutanoatehydrochloride and 2-fluoroethyl chloroformate according to the methoddescribed for Cap-47. ¹H NMR (500 MHz, DMSO-d₆) δ ppm 0.87 (t, J=6.71Hz, 6H) 1.97-2.10 (m, 1H) 3.83 (dd, J=8.39, 5.95 Hz, 1H) 4.14-4.18 (m,1H) 4.20-4.25 (m, 1H) 4.50-4.54 (m, 1H) 4.59-4.65 (m, 1H) 7.51 (d,J=8.54 Hz, 1H) 12.54 (s, 1H).

Cap-134 was prepared from (S)-diethyl alanine and methyl chloroformateaccording to the method described for Cap-51. ¹H NMR (500 MHz, DMSO-d₆)δ ppm 0.72-0.89 (m, 6H) 1.15-1.38 (m, 4H) 1.54-1.66 (m, 1H) 3.46-3.63(m, 3H) 4.09 (dd, J=8.85, 5.19 Hz, 1H) 7.24 (d, J=8.85 Hz, 1H) 12.55 (s,1H). LC (Cond. 2): RT=0.66 min; MS: Anal. Calcd. for [M+H]⁺ C₉H₁₈NO₄:204.12. found 204.02.

Biological Activity

An HCV Replion assay was utilized in the present disclosure, and wasprepared, conducted and validated as described in commonly ownedPCT/US2006/022197 and in O'Boyle et. al. Antimicrob Agents Chemother.2005 April; 49(4): 1346-53.

HCV 1b-377-neo replicon cells were used to test representative compoundsdescribed within this disclosure as were cells resistant to compound Adue to a Y2065H mutation in NS5A (described in applicationPCT/US2006/022197). The compounds tested were determined to have anapproximately 10-fold less inhibitory activity on cells resistant tocompound A than wild-type cells indicating a related mechanism of actionbetween the two compound series. Thus, the compounds can be effective tobe effective to inhibit the function of the HCV NS5A protein and areunderstood to be as effective in combinations as previously described inapplication PCT/US2006/022197 and commonly owned WO/04014852. Further,the compounds are effective against the HCV 1b genotype. It should alsobe understood that the compounds of the present disclosure can inhibitmultiple genotypes of HCV. Table 2 shows the EC50 values ofrepresentative compounds of the present disclosure against the HCV 1bgenotype. Ranges are as follows: A=1-10 μM; B=100-999 nM; C=1-99 nM; andD=10-999 pM.

TABLE 2 Example Number Structure Activity 30

C 31

D 32

D 33

D 34

D 35

C 36

D 37

D 38

D

The compounds of the present disclosure may inhibit HCV by mechanisms inaddition to or other than NS5A inhibition. In one embodiment thecompounds of the present disclosure inhibit HCV replicon and in anotherembodiment the compounds of the present disclosure inhibit NS5A.

It will be evident to one skilled in the art that the present disclosureis not limited to the foregoing illustrative examples, and that it canbe embodied in other specific forms without departing from the essentialattributes thereof. It is therefore desired that the examples beconsidered in all respects as illustrative and not restrictive,reference being made to the appended claims, rather than to theforegoing examples, and all changes which come within the meaning andrange of equivalency of the claims are therefore intended to be embracedtherein.

1. A compound of Formula (I)

or a pharmaceutically acceptable salt thereof, wherein A and B are eachphenyl; D and E are each five-membered aromatic rings containing one,two, or three heteroatoms independently selected from nitrogen, oxygen,and sulfur; provided that at least one of D and E is other thanimidazole; R¹ and R² are independently selected from hydrogen, R³—C(O)—;and each R³ is independently selected from alkoxy, alkoxyalkyl,alkoxycarbonyl, alkoxycarbonylalkyl, alkyl, alkylcarbonylalkyl, aryl,arylalkenyl, arylalkoxy, arylalkyl, aryloxyalkyl, cycloalkyl,(cycloalkyl)alkenyl, (cycloalkyl)alkyl, cycloalkyloxyalkyl, haloalkyl,heterocyclyl, heterocyclylalkenyl, heterocyclylalkoxy,heterocyclylalkyl, heterocyclyloxyalkyl, hydroxyalkyl, —NR^(c)R^(d),(NR^(c)R^(d))alkenyl, (NR^(c)R^(d))alkyl, and (NR^(c)R^(d))carbonyl. 2.The compound of claim 1, or a pharmaceutically acceptable salt thereof,wherein one of D and E is imidazole.
 3. The compound of claim 1, or apharmaceutically acceptable salt thereof, wherein at least one of D andE is selected from pyrazole, triazole, and oxadiazole.
 4. The compoundof claim 1, or a pharmaceutically acceptable salt thereof, wherein R³ isselected from alkoxy and arylalkyl.
 5. A compound of Formula (II)

or a pharmaceutically acceptable salt thereof, wherein D and E are eachfive-membered aromatic rings containing one, two, or three heteroatomsindependently selected from nitrogen, oxygen, and sulfur; provided thatat least one of D and E is other than imidazole; R³ and R⁴ areindependently selected from hydrogen and R³—C(O)—; and each R³ isindependently selected from alkoxy, alkoxyalkyl, alkoxycarbonyl,alkoxycarbonylalkyl, alkyl, alkylcarbonylalkyl, aryl, arylalkenyl,arylalkoxy, arylalkyl, aryloxyalkyl, cycloalkyl, (cycloalkyl)alkenyl,(cycloalkyl)alkyl, cycloalkyloxyalkyl, haloalkyl, heterocyclyl,heterocyclylalkenyl, heterocyclylalkoxy, heterocyclylalkyl,heterocyclyloxyalkyl, hydroxyalkyl, —NR^(c)R^(d), (NR^(c)R^(d))alkenyl,(NR^(c)R^(d))alkyl, and (NR^(c)R^(d))carbonyl.
 6. A compound of Formula(III)

or a pharmaceutically acceptable salt thereof, wherein D and E are eachfive-membered aromatic rings containing one, two, or three heteroatomsindependently selected from nitrogen, oxygen, and sulfur; provided thatat least one of D and E is other than imidazole; and provided that bothD and E are each substituted through carbon atoms; R¹ and R² areindependently selected from hydrogen and R³—C(O)—; and each R³ isindependently selected from alkoxy, alkoxyalkyl, alkoxycarbonyl,alkoxycarbonylalkyl, alkyl, alkylcarbonylalkyl, aryl, arylalkenyl,arylalkoxy, arylalkyl, aryloxyalkyl, cycloalkyl, (cycloalkyl)alkenyl,(cycloalkyl)alkyl, cycloalkyloxyalkyl, haloalkyl, heterocyclyl,heterocyclylalkenyl, heterocyclylalkoxy, heterocyclylalkyl,heterocyclyloxyalkyl, hydroxyalkyl, —NR^(c)R^(d), (NR^(c)R^(d))alkenyl,(NR^(c)R^(d))alkyl, and (NR^(c)R^(d))carbonyl.
 7. The compound of claim6, or a pharmaceutically acceptable salt thereof, wherein D and E areindependently selected from imidazole, pyrazole, triazole, andoxadiazole; provided at least one of D and E is other than imidazole;and provided that both D and E are each substituted through carbonatoms; and R³ is selected from alkoxy and arylalkyl.
 8. A compositioncomprising a compound of claim 1, or a pharmaceutically acceptable saltthereof, and a pharmaceutically acceptable carrier.
 9. The compositionof claim 8 further comprising one or two additional compounds havinganti-HCV activity wherein at least one of the additional compounds is aninterferon or a ribavirin.
 10. The composition of claim 9 wherein theinterferon is selected from interferon alpha 2B, pegylated interferonalpha, consensus interferon, interferon alpha 2A, and lymphoblastoidinterferon tau.
 11. A method of treating an HCV infection in a patient,comprising administering to the patient a therapeutically effectiveamount of a compound of claim 1, or a pharmaceutically acceptable saltthereof.
 12. The method of claim 11 further comprising administering oneor two additional compounds having anti-HCV activity prior to, after orsimultaneously with the compound of claim 1, or a pharmaceuticallyacceptable salt thereof wherein at least one of the additional compoundsis an interferon or a ribavirin.
 13. The method of claim 12 wherein theinterferon is selected from interferon alpha 2B, pegylated interferonalpha, consensus interferon, interferon alpha 2A, and lymphoblastoidinterferon tau.